8. what happens to matter during a chemical reaction

A new substance(product) is made from different elements(reactants) joined by chemical bonds

Explanation: To have a chemical reaction the chemical properties must change. Atoms are never created or destroyed during chemical reaction but at least one chemical bond is broken or formed. Evidence of a chemical change include: change of odor, change of color (for example, silver to reddish-brown when iron rusts), and change in temperature or energy, such as the production (exothermic) or loss (endothermic) of heat.

in 1783 cavendish was working with his hydrogen gas and found that when he burned it and condensed the vapor it was water. this was very significant since it disproved the greek theory of elements completely since water was not a simple substance but the product of two gases. it was lavoisier who hearing of the experiment gave cavendish's gas the name hydrogen ("water-producer") and added that hydrogen burned by combining with oxygen and that water was a hydrogen-oxygen combination.

explanation:

they all get energy from eating other animals, dead animals to be more precise.

hienas tends to steal pray from other animals. crows and vultures tend to eat dead animals and leftovers.

hope it ,

bioteacher101