Which best describes activation energy? A. the maximum amount of energy required to end a chemical reaction
B. the amount of energy absorbed in an endothermic reaction
C. the minimum amount of energy required to start a chemical reaction
D. the amount of energy released in an exothermic reaction

Which best explains how a heat pump can heat a room? cold air from the house is moved through pipes, where it absorbs thermal energy. warm air from outside is pushed into the house to replace the cold air. combustion warms the air when chemical energy is transferred to thermal energy. fuel is used to move a piston, which pushes warm air into the house.

Many farmers prefer cattle without horns because it is safer for their herds. the allele for no horns (n) is dominant to the allele for the presence of horns (n). a farmer mates a male with horns to a heterozygous female without horns. what is the chance that the offspring will have horns?

One of the reasons that stars are so large is because