Answer: CO 2 and H 2 O absorb outgoing infrared radiation from Earth but allow incoming visible light.
- A CO<sub>2</sub> and H<sub>2</sub>O absorb outgoing infrared radiation from Earth but allow incoming visible light
- B CO<sub>2</sub> blocks essentially all incoming sunlight before it reaches the surface during normal conditions
- C Ozone in the upper atmosphere absorbs outgoing infrared radiation as generally observed
- D Clouds uniformly block all incoming and outgoing radiation largely in typical laboratory settings
Correct answer: A. CO<sub>2</sub> and H<sub>2</sub>O absorb outgoing infrared radiation from Earth but allow incoming visible light
Explanation: Greenhouse gases are transparent to incoming solar visible light but absorb the longer-wavelength IR re-emitted by Earth. This traps heat, raising the temperature.
In an electromagnetic wave, the oscillating electric field (E) and magnetic field (B) are perpendicular to each other and to the direction the wave travels - a purely transverse wave that needs no medium, unlike sound.
Concept context
Maxwell's equations, EM spectrum, properties, and applications of each band.