What is the difference between thermal decomposition and combustion

Thermal decomposition refers to the formation of two or more products from a single reactant while combustion refers to reaction of a substance with oxygen to produce heat, light and other chemical substances.

Explanation:

An example of thermal decomposition is the formation of quick lime (calcium oxide)

CaCO3(s)> CaO(s) + CO2 (g)

heat

The two products were formed from a single reactant CaCO3

Combustion refers to the combination of a substance with oxygen, e.g, the combination of coke with oxygen:

C(s) + O2(g) > CO2(g)

Heat and light often accompany combustion reaction.

the leaf is an organ of a typical plant, and the main functions are to complete photosynthesis and allow the plant to exchange gas, just like how we have the respiratory system. leaves have the stomata, which collects maintains co2 and o2 levels. this is necessary for cell metabolism. the leaf also collects sunlight using chloroplasts. succinctly, leaves own a pivotal role in sustaining plant life.