An unknown substance has a mass of 21.7 g. The temperature of the substance increases by 19.7°C when 165 J of heat is added to the substance. The table lists the specific heats of select substances.

a chemical reaction happens

explanation:

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.