What is the primary source of solar energy that reaches the Earth?*1 pointInfrared radiationUltraviolet radiationVisible lightX-rays

The primary source of solar energy that reaches the Earth is the Sun. The Sun emits energy in various forms of radiation, with the majority of the energy reaching the Earth being in the form of visible light. This visible light is what plants use for photosynthesis and what warms the Earth's surface.

1. Infrared Radiation: While infrared radiation does contribute to the energy received from the Sun, it primarily involves heat, which is a type of energy but not the main source of solar power used in photosynthesis.

2. Ultraviolet Radiation: UV radiation is also emitted by the Sun and impacts biological processes (such as vitamin D synthesis in humans), but it constitutes a smaller fraction of the solar spectrum reaching Earth than visible light.

3. Visible Light: This is the predominant form of solar radiation that is harnessed by plants and utilized in photosynthesis, accounting for a significant portion of solar energy at the Earth's surface.

4. X-rays: X-rays are emitted by the Sun but are mostly absorbed by the Earth's atmosphere and do not reach the surface in significant amounts.

Final Answer

Visible light is the primary source of solar energy that reaches the Earth.