=COUNTIF(A2:A5,A2)+COUNTIF(A2:A5,A3) Counts the number of apples (the value in A2), and oranges (the value in A3) in cells A2 through A5. The result is 3. This formula uses COUNTIF twice to specify multiple criteria, one criteria per expression. You could also use the COUNTIFS function.
Punctuated equilibrium. Definition. noun. A theory that describes an evolutionary change happening rapidly and in brief geological events in between the long periods of stasis (or equilibrium). The theory is based on the stasis in fossil records, and when phenotypic evolution occurs, it is localized in rare, rapid events of branching speciation.
Equilibrium, Chemical. the state of a system in which one or more reversible chemical reactions occur and in which the forward and reverse rates for each reaction are equal. The composition of the system therefore remains constant so long as the conditions of its existence are preserved.hemical equilibrium. (chemistry). A condition in which a chemical reaction is occurring at equal rates in its forward and reverse directions, so that the concentrations of the reacting substances do not change with time. Also known as equilibrium.