Photosynthesis and cellular respiration are cells occur in cells.
a)chemical reactions.
b)physical reactions

A) chemical reactions.

Explanation:

"Photosynthesis is the process through which plants convert light energy into chemical energy. Here is the chemical reaction involved: As we can see, water and carbon dioxide combine to form glucose and oxygen. Since new chemical species are formed, photosynthesis is clearly a chemical change. "

volcanoes (an event in the geosphere) release a large amount of particulate matter into the atmosphere. these particles serve as nuclei for the formation of water droplets (hydrosphere). rainfall (hydrosphere) often increases following an eruption, stimulating plant growth (biosphere).