Hydrogen is placed separately from the other elements in the periodic table because it A. Is a gas
B. Has atomic number 1
C. Has many unique properties
D. Does not exist as a free element in nature

How are evaporation and sublimation similar? a both involve the formation of a gas. b both release energy to the surroundings. c both take place throughout a solid. d both take place at the surface of a liquid.

Areaction is first order with respect to reactant x and second order with respect to reactant y. which statement describes the rate law for this reaction?

Heat is the total potential energy of a substance that can be transferred. true false