Examkin

Physical Science

229 soru

Tüm türler229Çoktan seçmeli117Sayısal30Eşleştirme54Sıralama17Boşluk doldurma11
Soru 81Soru →

Complete the statement by providing the correct numerical coefficient and reaction classification for the chemical equation shown.

Aşağıdaki boşlukları doldurun

In the industrial synthesis of ammonia, the balanced chemical equation is $\text{N}_2 + \text{H}_2 \rightarrow 2\text{NH}_3$, and because multiple reactants combine into one compound, it is classified as a reaction.
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Cevap

The missing coefficient is 3 (or three) and the reaction type is synthesis (or combination).
To balance the equation according to the law of conservation of mass, the 6 hydrogen atoms in 2NH32\text{NH}_3 require a coefficient of 3 for diatomic H2\text{H}_2 (3×2=63 \times 2 = 6). A chemical process where two or more substances combine into a single compound is classified as a synthesis (or combination) reaction.

Adım Adım Çözüm

1
Count the total number of nitrogen and hydrogen atoms in the product molecules.
Two ammonia molecules (2NH32\text{NH}_3) contain 2×1=22 \times 1 = 2 nitrogen atoms and 2×3=62 \times 3 = 6 hydrogen atoms.
The law of conservation of mass dictates that the number of atoms of each element on the reactant side must equal the number of atoms on the product side.
2
Determine the coefficient needed for diatomic hydrogen gas (H2\text{H}_2) on the reactant side.
Dividing the required 6 hydrogen atoms by the 2 atoms per H2\text{H}_2 molecule yields a coefficient of 3.
Three molecules of H2\text{H}_2 supply exactly 6 hydrogen atoms (3×2=63 \times 2 = 6), completely balancing the equation.
3
Classify the reaction based on the relationship between reactants and products.
Two distinct elemental reactants (N2\text{N}_2 and H2\text{H}_2) combine chemically to produce a single product compound (NH3\text{NH}_3).
Reactions that follow the general form A+B→ABA + B \rightarrow AB are defined as synthesis or combination reactions.

Anahtar Kavram

Balancing chemical equations via conservation of mass and identifying synthesis reactions
Tahmini Süre:1m 0s
Soru 82Soru →

In laboratory science, matter is characterized by distinct physical, chemical, intensive, and extensive behaviors. Match each classification of matter or property on the left with its corresponding laboratory example on the right.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Öğeler

Intensive property
Extensive property
Chemical property
Physical change

Eşleşmeler

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Cevap

Intensive property correctly pairs with the boiling point of pure ethanol; Extensive property pairs with the total heat capacity of a ten-liter water sample; Chemical property pairs with the tendency of metallic iron to oxidize; Physical change pairs with the dissolution of crystalline table sugar into distilled water.
The correct pairings accurately reflect foundational physical science definitions: intensive properties (boiling point) are independent of system mass; extensive properties (total heat capacity) depend directly on the amount of matter; chemical properties (oxidation potential) govern reaction behavior; and physical changes (dissolution) preserve molecular structure.

Adım Adım Çözüm

1
Differentiate intensive from extensive physical properties.
Intensive properties (such as boiling point) are invariant with sample mass, whereas extensive properties (such as total heat capacity) scale directly with quantity.
This establishes the fundamental distinction between intrinsic substance characteristics and bulk quantity-dependent measurements.
2
Evaluate the chemical property descriptor.
The tendency of iron to oxidize describes a reactivity characteristic that involves forming new chemical bonds.
Chemical properties can only be observed or measured by attempting to change the chemical identity of the substance.
3
Analyze the dissolution process.
Dissolving sucrose in water is a reversible physical transformation where molecular composition remains intact.
Since no chemical bonds within the sucrose molecules are created or destroyed, the process is classified as a physical change.

Anahtar Kavram

Classification of Matter: Intensive vs. Extensive Properties, Chemical Properties, and Physical Transformations
Tahmini Süre:1m 30s
Soru 83Soru →

In an acid-base neutralization reaction, aqueous hydrochloric acid (HCl\text{HCl}) mixes with aqueous sodium hydroxide (NaOH\text{NaOH}) to produce table salt (NaCl\text{NaCl}) and one neutral compound. What is the chemical formula of the missing product in the balanced reaction below?

Aşağıdaki boşlukları doldurun

HCl+NaOH→NaCl+\text{HCl} + \text{NaOH} \rightarrow \text{NaCl} +
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Cevap

Water (H2OH_2O)
In a neutralization reaction between an acid and a base, hydrogen ions (H+H^+) from the acid combine with hydroxide ions (OH−OH^-) from the base to produce water (H2OH_2O). The remaining sodium (Na+Na^+) and chloride (Cl−Cl^-) ions form the salt sodium chloride (NaClNaCl). Therefore, the missing product that balances the equation is H2OH_2O.

Adım Adım Çözüm

1
Identify the characteristic reaction type and components.
Hydrochloric acid (HClHCl) is an acid and sodium hydroxide (NaOHNaOH) is a base, reacting in a classic neutralization reaction.
An acid and a base neutralize each other to produce a salt (NaClNaCl) and water.
2
Apply the law of conservation of mass to balance the atoms.
The reactants contain 2 hydrogen (HH) atoms, 1 chlorine (ClCl) atom, 1 sodium (NaNa) atom, and 1 oxygen (OO) atom. Subtracting the sodium and chlorine in NaClNaCl leaves 2 hydrogen atoms and 1 oxygen atom, which combine to form H2OH_2O.
Atoms cannot be created or destroyed in a chemical reaction; all reactant atoms must appear in the products.

Anahtar Kavram

Acid-Base Neutralization and Law of Conservation of Mass
Tahmini Süre:45s
Soru 84Soru →

Match each physical property of matter on the left with its corresponding definition on the right.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Öğeler

Malleability
Ductility
Viscosity
Density

Eşleşmeler

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Cevap

Malleability matches the ability to be hammered into thin sheets; Ductility matches the ability to be drawn into thin wires; Viscosity matches a fluid's resistance to flow; Density matches mass per unit volume.
Each physical property corresponds to a distinct observable behavior of matter: malleability allows flattening into sheets, ductility allows stretching into wires, viscosity measures resistance to liquid flow, and density expresses mass per unit volume.

Adım Adım Çözüm

1
Identify the definitions for solid mechanical properties.
Malleability corresponds to shaping into sheets under pressure, and ductility corresponds to drawing into wires under tension.
Both are intensive physical properties describing deformation of solids without altering chemical composition.
2
Identify the definitions for fluid and volumetric properties.
Viscosity corresponds to fluid flow resistance, and density corresponds to the mass-to-volume ratio.
Viscosity governs fluid dynamics, whereas density describes how tightly packed mass is in a given space.

Anahtar Kavram

Characteristic physical properties of matter
Tahmini Süre:45s
Soru 85Soru →

Match each fundamental physical law of mechanics to the statement that correctly describes it.

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Öğeler

Newton's First Law of Motion
Newton's Second Law of Motion
Newton's Third Law of Motion
Newton's Law of Universal Gravitation

Eşleşmeler

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Cevap

Newton's First Law pairs with the principle that an object maintains constant velocity unless acted on by an external net force; Newton's Second Law pairs with acceleration being proportional to net force and inversely proportional to mass (F=maF = ma); Newton's Third Law pairs with equal and opposite action-reaction forces; Newton's Law of Universal Gravitation pairs with mutual mass-dependent attraction that weakens with distance squared.
Each mechanics law corresponds to its standard scientific definition: the First Law defines inertia (constant velocity without net force), the Second Law establishes the relationship between force, mass, and acceleration (F=maF = ma), the Third Law describes equal and opposite interaction forces between bodies, and the Law of Universal Gravitation defines mutual mass attraction.

Adım Adım Çözüm

1
Identify the principle governing motion when the net force is zero.
This describes inertia, which is Newton's First Law.
An object resists changes to its velocity when no net force acts on it.
2
Identify the formula and relationship linking net force, mass, and acceleration.
This corresponds to F=maF = ma, which is Newton's Second Law.
Acceleration is produced when an unbalanced net force acts upon a given mass.
3
Identify the law governing force interactions between two distinct objects.
This corresponds to action-reaction pairs, which is Newton's Third Law.
Forces always act simultaneously in opposite directions on interacting bodies.
4
Identify the law describing mutual attraction between any two masses across space.
This corresponds to Newton's Law of Universal Gravitation.
Gravitational pull depends directly on the product of masses and inversely on distance squared.

Anahtar Kavram

Newton's Laws of Motion and Gravitation
Tahmini Süre:45s
Soru 86Soru →

An isotope of a neutral atom has a mass number of 3131 and contains 1616 neutrons in its nucleus. If this atom gains 33 electrons to form a stable anion, what is the total number of subatomic particles (protons, neutrons, and electrons) in the resulting ion?

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Cevap: 4949

Cevap

The total number of subatomic particles in the resulting ion is 4949.
The atomic number is found by subtracting neutrons from the mass number (31−16=1531 - 16 = 15 protons). A neutral atom has 1515 electrons, and gaining 33 electrons increases the electron count to 1818. Adding 1515 protons, 1616 neutrons, and 1818 electrons gives a total of 4949 subatomic particles.

Adım Adım Çözüm

1
Determine the number of protons in the atom.
1515 protons
The atomic number equals the mass number minus the number of neutrons: 31−16=1531 - 16 = 15.
2
Determine the number of electrons in the resulting anion.
1818 electrons
A neutral atom has equal numbers of protons and electrons (1515). Gaining 33 electrons yields 15+3=1815 + 3 = 18 electrons.
3
Sum all subatomic particles (protons, neutrons, and electrons) in the ion.
15+16+18=4915 + 16 + 18 = 49
The total particle count is the sum of 1515 protons, 1616 neutrons, and 1818 electrons.

Anahtar Kavram

Calculating subatomic particle totals in ions using mass number and charge
Tahmini Süre:1m 30s
Soru 87Soru →

An automotive technician performs several actions on a piece of iron: cutting it to size, polishing its surface, heating it to bend it into shape, and leaving an unpainted scrap outside where it eventually forms reddish-brown rust. Which of these actions results in a chemical change?

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Cevap: Rusting after being exposed to outside air

Cevap

Rusting after being exposed to outside air
Rusting is a chemical change because iron atoms react with oxygen in the atmosphere to create an entirely new compound, iron oxide.

Adım Adım Çözüm

1
Define the difference between physical and chemical changes.
A physical change alters form, shape, or appearance without changing the underlying chemical identity. A chemical change produces one or more new substances with different chemical properties.
Understanding the fundamental criteria distinguishes changes in state/shape from chemical reactions.
2
Evaluate cutting, polishing, and heating/bending.
These actions modify only the size, surface texture, and shape of the iron, while the substance remains pure iron (FeFe).
Changes in dimensions and mechanical deformation do not alter chemical bonds.
3
Evaluate the process of rusting.
Iron exposed to moisture and oxygen undergoes oxidation to form iron(III) oxide (Fe2O3Fe_2O_3), a completely new substance.
The creation of a new compound with distinct chemical properties defines a chemical change.

Anahtar Kavram

Physical versus Chemical Changes in Matter
Soru 88Soru →

A double-walled cryogenic storage container is engineered to maintain liquid nitrogen at extremely low temperatures by minimizing heat gain from the surrounding environment. Which of the following correctly pairs a structural feature of the container with the primary heat transfer mechanism it is designed to inhibit?

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Cevap: The silvered, mirror-like surface lining the walls primarily minimizes heat gain caused by thermal radiation.

Cevap

The silvered, mirror-like surface lining the walls primarily minimizes heat gain caused by thermal radiation.
Thermal radiation transfers energy through electromagnetic infrared waves and does not require particles or a material medium. Highly polished, silvered surfaces reflect these electromagnetic waves away from the inner chamber, significantly reducing radiative heat gain.

Adım Adım Çözüm

1
Analyze the physical requirements of the three fundamental heat transfer mechanisms.
Conduction transfers kinetic energy through direct contact of particles in solids, convection transfers heat through the bulk movement of fluids (liquids or gases), and radiation transfers energy via electromagnetic waves without requiring any physical medium.
Understanding whether each transfer mechanism depends on matter is necessary to evaluate the function of each insulating barrier.
2
Examine how each specific component of the cryogenic container operates.
The evacuated space between the walls eliminates particles, blocking conduction and convection; the narrow composite neck reduces cross-sectional contact area, reducing solid conduction; the reflective silver lining reflects infrared electromagnetic waves.
Matching structural components to their physical principles reveals which pairing is scientifically valid.
3
Evaluate the pairing of the reflective lining with thermal radiation.
Because thermal radiation travels across the vacuum gap as electromagnetic waves, highly polished reflective surfaces are required to reflect these waves away from the cold storage chamber.
This confirms that the silvered surface specifically targets and mitigates radiative heat transfer.

Anahtar Kavram

Thermal Heat Transfer Mechanisms (Conduction, Convection, and Radiation)
Tahmini Süre:1m 15s
Soru 89Soru →

In an industrial chemical synthesis process, methane gas (CH4\text{CH}_4) reacts with high-temperature steam (H2O\text{H}_2\text{O}) to yield carbon monoxide (CO\text{CO}) and hydrogen gas (H2\text{H}_2) according to the following chemical equation:

CH4+H2O→CO+?‾H2\text{CH}_4 + \text{H}_2\text{O} \rightarrow \text{CO} + \underline{\quad ? \quad}\text{H}_2

What numerical coefficient must be placed in front of H2\text{H}_2 to balance the equation?

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Cevap: 3

Cevap

The numerical coefficient that balances the equation is 3.
The reactant side has a total of 6 hydrogen atoms: 4 from methane (CH4\text{CH}_4) and 2 from steam (H2O\text{H}_2\text{O}). Since molecular hydrogen gas is diatomic (H2\text{H}_2), a coefficient of 3 provides 3×2=63 \times 2 = 6 hydrogen atoms, successfully satisfying the Law of Conservation of Mass while leaving carbon and oxygen balanced at 1 atom each on both sides.

Adım Adım Çözüm

1
Tally the number of each type of atom on the reactant side of the equation.
Reactants: 1 Carbon atom (from CH4\text{CH}_4), 6 Hydrogen atoms (4 from CH4\text{CH}_4 plus 2 from H2O\text{H}_2\text{O}), and 1 Oxygen atom (from H2O\text{H}_2\text{O}).
According to the Law of Conservation of Mass, atoms cannot be created or destroyed, so total reactant atoms must equal total product atoms.
2
Tally the fixed atoms on the product side.
Products: 1 Carbon atom (in CO\text{CO}) and 1 Oxygen atom (in CO\text{CO}). Carbon and oxygen are already balanced (1 of each on both sides).
Identifies which elements are already balanced so attention can be directed to the unbalanced element.
3
Determine the required coefficient for diatomic hydrogen (H2\text{H}_2) to balance hydrogen.
To supply 6 hydrogen atoms using diatomic H2\text{H}_2 molecules: 6÷2=36 \div 2 = 3.
Multiplying the coefficient 3 by the subscript 2 yields 6 hydrogen atoms, balancing the equation.

Anahtar Kavram

Balancing Chemical Equations and Conservation of Mass
Tahmini Süre:1m 0s
Soru 90Soru →

When methane gas (CH4\text{CH}_4) burns in the presence of oxygen gas (O2\text{O}_2), it reacts to produce carbon dioxide (CO2\text{CO}_2) and water vapor (H2O\text{H}_2\text{O}). Which of the following statements correctly describes what happens to the atoms during this chemical reaction?

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Cevap: The existing atoms break their original bonds and rearrange to form new chemical compounds.

Cevap

The existing atoms break their original bonds and rearrange to form new chemical compounds.
In a chemical reaction, the original chemical bonds between reactant atoms break, and the atoms rearrange to form new bonds and produce distinct substances without creating or destroying any atoms.

Adım Adım Çözüm

1
Identify the nature of the process described in the prompt.
The combustion of methane with oxygen is a chemical reaction that generates new substances (CO2\text{CO}_2 and H2O\text{H}_2\text{O}).
A chemical reaction involves a change in chemical identity and composition, unlike a simple phase change.
2
Apply the principles of atomic theory and the Law of Conservation of Mass to the reaction.
The total number and identity of each atom remain constant, but the chemical bonds holding them together break and reform into new molecular structures.
Chemical reactions involve the rearrangement of valence electrons and chemical bonds between atoms, not the destruction or elemental transformation of atoms.

Anahtar Kavram

During a chemical reaction, existing chemical bonds are broken and atoms rearrange into new combinations to form different chemical compounds while conserving all atoms.
Tahmini Süre:45s
Soru 91Soru →

Read the chemical reaction scenario below and fill in the blanks with the correct numbers or terms.

Aşağıdaki boşlukları doldurun

During the complete combustion of butane (C4H10C_4H_{10}), the hydrocarbon reacts with oxygen gas (O2O_2) to produce carbon dioxide (CO2CO_2) and water vapor (H2OH_2O). When this chemical equation is balanced using the smallest possible whole numbers, the coefficient for oxygen (O2O_2) is and the sum of all coefficients in the balanced equation is . Furthermore, because this process releases net thermal energy to its surroundings, it is thermodynamically classified as an reaction.
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Cevap

The balanced coefficient for oxygen is 13, the sum of all coefficients is 33, and the reaction is exothermic.
Balancing the complete combustion of butane requires compensating for an odd number of oxygen atoms on the product side by doubling all coefficients. This transforms the intermediate equation (C4H10+6.5O2→4CO2+5H2OC_4H_{10} + 6.5O_2 \rightarrow 4CO_2 + 5H_2O) into the proper whole-number equation (2C4H10+13O2→8CO2+10H2O2C_4H_{10} + 13O_2 \rightarrow 8CO_2 + 10H_2O). The resulting oxygen coefficient is 13, and the total sum of coefficients is 2 + 13 + 8 + 10 = 33. Because the combustion process releases net thermal energy, it is classified as an exothermic reaction.

Adım Adım Çözüm

1
Write the unbalanced skeletal equation for the combustion reaction.
C4H10+O2→CO2+H2OC_4H_{10} + O_2 \rightarrow CO_2 + H_2O
Establishes the chemical formulas for all reactants and products before applying the law of conservation of mass.
2
Balance the carbon (C) and hydrogen (H) atoms first.
C4H10+O2→4CO2+5H2OC_4H_{10} + O_2 \rightarrow 4CO_2 + 5H_2O
There are 4 carbons and 10 hydrogens in a butane molecule, requiring 4 molecules of carbon dioxide and 5 molecules of water to balance those elements.
3
Count the oxygen (O) atoms on the product side to determine the required oxygen on the reactant side.
Products have (4×2)+(5×1)=13(4 \times 2) + (5 \times 1) = 13 oxygen atoms. The reactants need 132\frac{13}{2} O2O_2 molecules.
Oxygen appears in only one reactant but multiple products, making it most efficient to balance last.
4
Multiply the entire equation by 2 to achieve the smallest whole-number coefficients.
2C4H10+13O2→8CO2+10H2O2C_4H_{10} + 13O_2 \rightarrow 8CO_2 + 10H_2O
Standard chemical equations require the lowest possible whole-number coefficients, eliminating the fractional 6.5.
5
Identify the coefficient for oxygen and calculate the total sum of all coefficients.
Oxygen coefficient = 13. Sum = 2+13+8+10=332 + 13 + 8 + 10 = 33.
This directly answers the first two blanks of the prompt based on the fully balanced equation.
6
Classify the reaction type based on its thermal energy transfer.
Exothermic.
Combustion reactions release heat energy into their surroundings, which is the definition of an exothermic process.

Anahtar Kavram

Advanced Stoichiometry and Thermochemistry
Soru 92Soru →

A sealed, hollow cylinder made of solid metal (density =6.0 g/cm3= 6.0 \text{ g/cm}^3) is placed in a liquid solvent (density =1.5 g/cm3= 1.5 \text{ g/cm}^3). The cylinder achieves neutral buoyancy, meaning it floats completely submerged without sinking or rising. If the total outer volume of the cylinder is 400 cm3400 \text{ cm}^3, what is the volume of the hollow cavity inside the cylinder in cm3\text{cm}^3?

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Cevap: 300

Cevap

300
For the cylinder to be neutrally buoyant, its total mass divided by its total volume must equal the fluid's density of 1.5 g/cm31.5 \text{ g/cm}^3. With a total volume of 400 cm3400 \text{ cm}^3, the cylinder's total mass is 600 g600 \text{ g}. Since the entire mass comes from the metal shell, dividing this 600 g600 \text{ g} by the metal's true density (6.0 g/cm36.0 \text{ g/cm}^3) reveals that the actual metal occupies 100 cm3100 \text{ cm}^3. The remaining volume (400−100400 - 100) must be the 300 cm3300 \text{ cm}^3 hollow cavity.

Adım Adım Çözüm

1
Determine the average density required for neutral buoyancy.
Average density = 1.5 g/cm31.5 \text{ g/cm}^3
An object that floats completely submerged (neutrally buoyant) must have an overall density exactly equal to the fluid it displaces.
2
Calculate the total mass of the cylinder.
Total mass = 600 g600 \text{ g}
Mass equals the overall average density multiplied by total volume (1.5×4001.5 \times 400).
3
Calculate the volume occupied by the solid metal itself.
Metal volume = 100 cm3100 \text{ cm}^3
The solid metal volume equals the total mass divided by the solid metal's density (600/6.0600 / 6.0). The hollow cavity contributes essentially zero mass.
4
Calculate the volume of the hollow cavity.
Cavity volume = 300 cm3300 \text{ cm}^3
The cavity volume is the total outer volume minus the volume of the solid metal (400−100400 - 100).

Anahtar Kavram

Density, extensive/intensive properties, and buoyancy of composite objects
Soru 93Soru →

A delivery van travels along a circular entrance ramp at a constant speed of 25 mph25\text{ mph}. Why is the vehicle considered to be accelerating even though the speedometer reading remains unchanged?

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Cevap: The direction of travel is constantly changing, which alters the vehicle's velocity.

Cevap

The direction of travel is constantly changing, which alters the vehicle's velocity.
Acceleration is defined in physics as the rate of change of velocity over time. Because velocity is a vector quantity consisting of both speed and direction, an object traveling in a circle is continuously changing its direction. This continuous change in direction means the velocity vector is changing, which produces acceleration directed toward the center of the turn.

Adım Adım Çözüm

1
Define the relationship between speed, velocity, and acceleration
Speed is a scalar quantity (magnitude only), whereas velocity is a vector quantity (both magnitude and direction). Acceleration (aa) is the rate of change of velocity: a=ΔvΔta = \frac{\Delta v}{\Delta t}.
Determining whether an object is accelerating requires evaluating its velocity vector rather than just its scalar speed.
2
Analyze the motion of the vehicle on a curved path
Although the magnitude of the velocity (speed) is steady at 25 mph25\text{ mph}, the direction of travel continuously turns along the curve.
A change in the direction of a vector constitutes a change in velocity.
3
Conclude whether acceleration occurs
Because velocity changes continuously with direction, the vehicle undergoes centripetal acceleration directed toward the center of the curve.
Any non-zero change in velocity over time confirms acceleration.

Anahtar Kavram

Velocity is a vector quantity comprising both magnitude and direction; thus, changing direction at constant speed results in acceleration.
Tahmini Süre:45s
Soru 94Soru →

Match each thermodynamic principle or heat transfer mechanism with the real-world scenario where it serves as the primary mode of thermal energy exchange.

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Öğeler

Direct kinetic energy transfer through microscopic particle collisions within a solid material
Bulk fluid displacement driven by buoyancy forces arising from temperature-induced density gradients
Thermal energy emission and propagation via electromagnetic waves across empty space
Isothermal energy absorption dedicated to overcoming intermolecular bonds during a phase transition

Eşleşmeler

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Cevap

Direct kinetic energy transfer via collisions matches copper heat sink dissipation (conduction); bulk fluid displacement driven by density differences matches coastal sea breezes (convection); electromagnetic emission across empty space matches solar atmospheric warming (radiation); and isothermal phase-change energy absorption matches evaporative sweat cooling (latent heat).
Each thermodynamic mechanism is accurately paired with its primary real-world application: conduction governs kinetic transport through solid copper, convection governs atmospheric buoyancy circulation cells, radiation governs electromagnetic transfer across the vacuum of space, and latent heat governs the isothermal phase change of evaporating sweat.

Adım Adım Çözüm

1
Identify the fundamental heat transfer mechanism described in each item on the left.
The left descriptions represent thermal conduction, natural convection, thermal radiation, and latent heat of vaporization, respectively.
Categorizing each physical description by its formal thermodynamic definition clarifies the governing laws of energy transport.
2
Analyze each scenario on the right to identify the dominant thermodynamic mechanism in operation.
The copper baseplate operates via solid conduction, coastal breezes operate via fluid convection, solar warming operates via radiative wave transport through a vacuum, and sweat evaporation operates via latent heat absorption.
Matching real-world physical systems to their underlying thermal transfer modes isolates the correct pairings.
3
Pair the theoretical definitions with their corresponding empirical physical scenarios.
Conduction pairs with the copper baseplate; convection pairs with coastal breeze circulation; radiation pairs with solar warming across space; latent heat pairs with sweat evaporation.
Ensures every description is paired unambiguously with its sole physical manifestation.

Anahtar Kavram

Distinguishing between microscopic conduction, macroscopic buoyant convection, electromagnetic radiation, and latent heat phase transitions in physical systems.
Tahmini Süre:1m 30s
Soru 95Soru →

A divalent metal cation (M2+M^{2+}) contains 1818 electrons. In the nucleus of this isotope, the number of neutrons is 44 greater than the number of protons. What is the mass number of this isotope?

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Cevap: 44

Cevap

The mass number of this isotope is 4444.
A neutral atom that forms a divalent cation (M2+M^{2+}) loses 22 electrons. Since the cation has 1818 electrons, the neutral atom has 2020 electrons and therefore 2020 protons. The isotope has 44 more neutrons than protons, giving 20+4=2420 + 4 = 24 neutrons. The mass number is the sum of protons and neutrons: 20+24=4420 + 24 = 44.

Adım Adım Çözüm

1
Determine the atomic number (number of protons) from the cation's charge and electron configuration.
Protons = 2020
A divalent cation (M2+M^{2+}) has lost 22 electrons relative to its neutral state. The neutral atom therefore has 18+2=2018 + 2 = 20 electrons and, correspondingly, 2020 protons.
2
Calculate the total number of neutrons in the nucleus.
Neutrons = 2424
The problem specifies that the number of neutrons exceeds the number of protons by 44, giving 20+4=2420 + 4 = 24 neutrons.
3
Sum the protons and neutrons to obtain the mass number (AA).
Mass number = 4444
The mass number of an isotope is defined as the total number of nucleons (protons plus neutrons): 20+24=4420 + 24 = 44.

Anahtar Kavram

Calculation of atomic number and mass number from ionic charge and subatomic particle relationships.
Tahmini Süre:1m 30s
Soru 96Soru →

Match each primary mechanism of heat transfer to the everyday scenario that best exemplifies it.

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Öğeler

Conduction
Convection
Radiation

Eşleşmeler

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Cevap

Conduction matches the metal spoon heating up in hot soup; Convection matches warm air rising toward the ceiling while cool air sinks; Radiation matches feeling the warmth of sunlight on your skin through a window.
Thermal energy transfer operates through three fundamental pathways. Conduction occurs via direct physical contact where kinetic energy passes between neighboring particles, perfectly illustrated by the solid metal spoon heating up. Convection occurs in fluids (gases and liquids) as temperature variations cause density changes, producing convective currents where warmer, less dense air rises toward the ceiling. Radiation transfers heat via electromagnetic waves that travel across space independently of physical particle movement, as observed when sunlight warms the skin.

Adım Adım Çözüm

1
Identify the physical state and mechanism for the first item (Conduction).
Conduction requires direct atomic or molecular contact within a solid or stationary material. The metal spoon in direct contact with hot soup represents this process.
Solids, especially metallic conductors, transfer heat along a temperature gradient via particle vibration and free electron movement.
2
Identify the physical state and mechanism for the second item (Convection).
Convection involves the macroscopic flow of fluids (liquids or gases). Air expanding, becoming less dense, and rising sets up a natural convection loop.
Temperature changes alter fluid density, generating buoyant upward forces for warm fluid and downward settling of cooler fluid.
3
Identify the physical state and mechanism for the third item (Radiation).
Radiation involves electromagnetic waves capable of traveling through a vacuum or transparent media like glass. Sunlight warming skin is radiant energy transfer.
Thermal radiation does not rely on matter-to-matter contact or circulating fluid streams to transport energy.

Anahtar Kavram

Distinct mechanisms of thermal energy transfer: conduction (direct contact), convection (fluid movement), and radiation (electromagnetic waves).
Tahmini Süre:45s
Soru 97Soru →

A technician inspects a solid metal component with a mass of 108 g108\text{ g} and a volume of 12 cm312\text{ cm}^3. What is the density of the component in grams per cubic centimeter (g/cm3\text{g/cm}^3)?

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Cevap: 9

Cevap

9 g/cm^3
Density measures the amount of mass contained per unit volume of a substance. Dividing the component's mass of 108 g108\text{ g} by its volume of 12 cm312\text{ cm}^3 gives a density of 9 g/cm39\text{ g/cm}^3.

Adım Adım Çözüm

1
Identify the given physical quantities from the problem statement
Mass (mm) = 108 g108\text{ g}, Volume (VV) = 12 cm312\text{ cm}^3
Density is a fundamental physical property defined as mass per unit volume.
2
Calculate the density using the formula Density=MassVolume\text{Density} = \frac{\text{Mass}}{\text{Volume}}
Density=108 g12 cm3=9 g/cm3\text{Density} = \frac{108\text{ g}}{12\text{ cm}^3} = 9\text{ g/cm}^3
Dividing the total mass of the object by its volume determines the mass contained in each cubic centimeter.

Anahtar Kavram

Density as a characteristic physical property of matter relating mass and volume
Tahmini Süre:45s
Soru 98Soru →

Four electric hoists in a maintenance facility lift cargo vertically at constant speeds. Arrange the hoists in order of their average mechanical power output, from lowest power to highest power.

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Cevap

The correct sequence from lowest to highest mechanical power is the hoist delivering 400 W400\text{ W} (500 N×4 m/5 s500\text{ N} \times 4\text{ m} / 5\text{ s}), followed by the hoist delivering 500 W500\text{ W} (250 N×10 m/5 s250\text{ N} \times 10\text{ m} / 5\text{ s}), then the hoist delivering 600 W600\text{ W} (300 N×6 m/3 s300\text{ N} \times 6\text{ m} / 3\text{ s}), and ending with the hoist delivering 800 W800\text{ W} (800 N×3 m/3 s800\text{ N} \times 3\text{ m} / 3\text{ s}).
Mechanical power equals the rate of doing work (P=F×dtP = \frac{F \times d}{t}). Computing the power output yields 400 W400\text{ W} for the 500 N500\text{ N} load over 4 m4\text{ m} in 5 s5\text{ s}, 500 W500\text{ W} for the 250 N250\text{ N} load over 10 m10\text{ m} in 5 s5\text{ s}, 600 W600\text{ W} for the 300 N300\text{ N} load over 6 m6\text{ m} in 3 s3\text{ s}, and 800 W800\text{ W} for the 800 N800\text{ N} load over 3 m3\text{ m} in 3 s3\text{ s}. This produces the ascending sequence 400 W→500 W→600 W→800 W400\text{ W} \rightarrow 500\text{ W} \rightarrow 600\text{ W} \rightarrow 800\text{ W}.

Adım Adım Çözüm

1
Recall the formula for mechanical power in terms of force, distance, and time.
P=Wt=F×dtP = \frac{W}{t} = \frac{F \times d}{t} where power (PP) is in Watts (W\text{W}), force (FF) in Newtons (N\text{N}), distance (dd) in meters (m\text{m}), and time (tt) in seconds (s\text{s}).
Power measures the rate at which work is performed.
2
Calculate the power output for each hoist.
First hoist: (300 N×6 m)/3 s=1800 J/3 s=600 W(300\text{ N} \times 6\text{ m}) / 3\text{ s} = 1800\text{ J} / 3\text{ s} = 600\text{ W}. Second hoist: (500 N×4 m)/5 s=2000 J/5 s=400 W(500\text{ N} \times 4\text{ m}) / 5\text{ s} = 2000\text{ J} / 5\text{ s} = 400\text{ W}. Third hoist: (800 N×3 m)/3 s=2400 J/3 s=800 W(800\text{ N} \times 3\text{ m}) / 3\text{ s} = 2400\text{ J} / 3\text{ s} = 800\text{ W}. Fourth hoist: (250 N×10 m)/5 s=2500 J/5 s=500 W(250\text{ N} \times 10\text{ m}) / 5\text{ s} = 2500\text{ J} / 5\text{ s} = 500\text{ W}.
Determines the exact numerical power for all four mechanical scenarios.
3
Arrange the resulting power values in ascending order.
400 W<500 W<600 W<800 W400\text{ W} < 500\text{ W} < 600\text{ W} < 800\text{ W}.
Satisfies the requirement to order from lowest power to highest power.

Anahtar Kavram

Power is the rate of doing work, defined as work divided by time (P=Wt=F×dtP = \frac{W}{t} = \frac{F \times d}{t}), and is measured in Watts.
Tahmini Süre:1m 15s
Soru 99Soru →

A motorized winch pulls a cable, accelerating a load from rest (0 m/s0\text{ m/s}) to a final velocity of 18 m/s18\text{ m/s} in 6 seconds6\text{ seconds} at a constant rate. What is the acceleration of the load in meters per second squared (m/s2\text{m/s}^2)?

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Cevap: 3

Cevap

The acceleration of the load is 3 m/s23\text{ m/s}^2.
Acceleration is calculated by dividing the total change in velocity by the elapsed time (a=Δvta = \frac{\Delta v}{t}). Because the load accelerates uniformly from 0 m/s0\text{ m/s} to 18 m/s18\text{ m/s} over 6 s6\text{ s}, the acceleration is 18 m/s−0 m/s6 s=3 m/s2\frac{18\text{ m/s} - 0\text{ m/s}}{6\text{ s}} = 3\text{ m/s}^2.

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1
Identify the initial velocity, final velocity, and elapsed time from the given problem.
vi=0 m/sv_i = 0\text{ m/s}, vf=18 m/sv_f = 18\text{ m/s}, and t=6 st = 6\text{ s}
These parameters are required to calculate uniform linear acceleration.
2
Set up the acceleration formula: a=Δvt=vf−vita = \frac{\Delta v}{t} = \frac{v_f - v_i}{t}.
a=18−06a = \frac{18 - 0}{6}
Acceleration represents the rate of change of velocity with respect to time.
3
Perform the division to compute the numerical value.
a=3 m/s2a = 3\text{ m/s}^2
Dividing 18 m/s18\text{ m/s} by 6 s6\text{ s} yields 3 m/s23\text{ m/s}^2.

Anahtar Kavram

Linear acceleration is defined as the change in velocity divided by the time interval over which the change occurs (a=Δvta = \frac{\Delta v}{t}).
Tahmini Süre:45s
Soru 100Soru →

Two solid samples of equal mass, Substance A and Substance B, are heated in separate insulated containers at the exact same constant rate. During the heating process, Substance A exhibits a much steeper rate of temperature increase prior to melting, but requires three times as much time to fully melt at its melting point compared to Substance B. Which of the following conclusions correctly compares the thermal properties of Substance A to Substance B?

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Cevap: Substance A has a lower specific heat capacity and a higher latent heat of fusion than Substance B.

Cevap

Substance A has a lower specific heat capacity and a higher latent heat of fusion than Substance B.
Specific heat capacity (cc) measures the thermal energy required to raise the temperature of a given mass (Q=mcΔTQ = mc\Delta T). Under identical mass and heat supply, a steeper slope (faster temperature rise) signifies a lower specific heat capacity. Latent heat of fusion (LfL_f) governs the energy absorbed at a constant temperature during melting (Q=mLfQ = mL_f). A longer duration spent in the solid-to-liquid plateau indicates that a greater amount of energy was required to completely melt the sample, proving Substance A has a higher latent heat of fusion.

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1
Analyze the rate of temperature rise before phase change in relation to specific heat capacity.
The rate of temperature increase is inversely proportional to specific heat capacity (c=QmΔTc = \frac{Q}{m \Delta T}). Because both samples have identical mass and heat input rates, a steeper temperature increase means Substance A requires less energy per degree change, indicating a lower specific heat capacity.
Specific heat capacity defines the amount of thermal energy required to raise the temperature of a unit mass by one degree.
2
Analyze the duration of the melting phase transition in relation to latent heat of fusion.
The energy absorbed during melting at constant temperature is given by Q=mLfQ = m L_f. Because the heating rate is constant, taking three times as long to melt means Substance A absorbs three times more energy during phase change, indicating a higher latent heat of fusion.
Latent heat of fusion defines the energy required to change a substance from solid to liquid at its melting point without a change in temperature.
3
Combine the deduced properties to determine the correct relationship.
Substance A possesses a lower specific heat capacity and a higher latent heat of fusion compared to Substance B.
Synthesizes the solid-state heating behavior and the isothermal phase transition behavior.

Anahtar Kavram

Relationship between heating curve slopes, specific heat capacity, and latent heat of fusion
Tahmini Süre:1m 30s
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