Which of the following statements best describes the relationship between any point on an ellipse and each of its two foci?
A. The quotient of the distances to each focus equals a certain
constant.
B. The product of the distances to each focus equals a certain
constant.
C. The sum of the distances to each focus equals a certain constant.
D. The difference of the distances to each focus equals a certain
constant.

answer

fusion: the energy source of stars. the energy released from the collapse of the gas into a protostar causes the center of the protostar to become extremely hot. when the core is hot enough, nuclear fusion commences. fusion is the process where two hydrogen atoms combine to form a helium atom, releasing energy.

hope it

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.