The equator is warmer than the poles because the Sun's energy is more ____________________________ at the equator than at the poles.

• A. Concentrated
• B. Spread Out
• C. Diffuse
• D. Reflected

Answer: (A)

The main idea is that sunlight delivers more energy per unit area when it hits directly. At the equator, the Sun’s rays come in roughly from above, so they are more perpendicular to the surface and energy is concentrated on a smaller area, which heats the surface more. Toward the poles, the Sun’s rays strike at a slant, spreading the same amount of energy over a larger area and over fewer hours of daylight, reducing the heat. So energy being concentrated at the equator explains why it’s warmer there.

If energy were spread out, or if we described the light as diffuse or mostly reflected, it wouldn’t capture the key effect—the angle of incidence changing the energy density on the surface.