Six runners compete in the 100-meter hurdle event by each jumping 10 hurdles, one at a time. (Runners must jump the hurdles in his or her lane.)
Would we use this as an analogy for a series circuit, a parallel circuit, or both?
Why?

it's filtration, but this is an assumption so my apologies if i got this

answer carbon and three oxygen atoms;

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.