A spring-fed stream forms a pond that contains watercress plants, minnows, and crayfish. The pond receives 5 hours of direct sunlight every day. Which of the following is an abiotic factor in this ecosystem? the pond water

the watercress plants

the minnows

the crayfish

the minnows

Explanation:

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.