Examkin

Question

Difficulty: MediumWaves, Sound, and Light

Electromagnetic radiation travels through space as oscillating electric and magnetic fields, with each type characterized by its specific frequency, wavelength, and energy. Arrange the following regions of the electromagnetic spectrum in order of increasing photon energy, from the lowest energy to the highest energy.

  1. 1Radio waves
  2. 2Microwaves
  3. 3Visible light
  4. 4Ultraviolet radiation
  5. 5X-rays

Answer

The correct sequence from lowest to highest photon energy is Radio waves, Microwaves, Visible light, Ultraviolet radiation, and X-rays.
Photon energy is governed by the relation E=hf=hcλE = hf = \frac{hc}{\lambda}, where hh is Planck's constant and cc is the speed of light. Because energy increases directly with frequency and inversely with wavelength, radiation with the longest wavelengths (radio waves) carries the least energy per photon, followed in ascending order by microwaves, visible light, ultraviolet radiation, and X-rays.

Step-by-Step Solution

1
Recall the fundamental relationship between wave frequency and photon energy.
Photon energy is directly proportional to frequency as defined by Planck's equation, E=hfE = hf, and inversely proportional to wavelength, E=hcλE = \frac{hc}{\lambda}.
Establishing that higher frequency and shorter wavelength correspond directly to higher photon energy.
2
Identify the positions of the given wave types across the continuous electromagnetic spectrum.
In order of increasing frequency: Radio waves (<109 Hz< 10^9\text{ Hz}) →\rightarrow Microwaves (109−1012 Hz10^9 - 10^{12}\text{ Hz}) →\rightarrow Visible light (4×1014−7.5×1014 Hz4 \times 10^{14} - 7.5 \times 10^{14}\text{ Hz}) →\rightarrow Ultraviolet radiation (1015−1016 Hz10^{15} - 10^{16}\text{ Hz}) →\rightarrow X-rays (1016−1019 Hz10^{16} - 10^{19}\text{ Hz}).
Classifying each radiation type by its frequency band determines its relative energy.
3
Sequence the items from the lowest photon energy to the highest photon energy.
Radio waves →\rightarrow Microwaves →\rightarrow Visible light →\rightarrow Ultraviolet radiation →\rightarrow X-rays.
Arranging the items in ascending order of frequency matches the required ascending order of energy.

Key Concept

Photon energy across the electromagnetic spectrum is directly proportional to wave frequency (E=hfE = hf) and inversely proportional to wavelength (E=hc/λE = hc/\lambda).
Estimated Time:1m 0s
Rate this question

Topics

Waves, Sound, and Light

More questions from this topic