Fossil fuels contain chemical energy stored in the form of carbon-hydrogen bonds. This chemical energy originally came from radiant energy captured through photosynthesis.

Here's a breakdown:

1. Radiant energy from the sun is absorbed by plants during photosynthesis.

2. Photosynthesis converts this radiant energy into chemical energy, storing it in the form of carbohydrates (like sugars and starches).

3. Over millions of years, these plants are buried and subjected to heat and pressure.

4. This process transforms the carbohydrates into hydrocarbons, which are the primary components of fossil fuels like coal, oil, and natural gas.

Essentially, the carbon-hydrogen bonds in fossil fuels hold the stored energy from the sun that was captured during photosynthesis. When we burn fossil fuels, we are releasing this stored energy back into the environment.