What is the energy released or absorbed as heat when one mole of a compound is produced by combination of its elements? select one: a. heat of combustion b. free energy c. entropy d. heat of formation?

Select each correct answer. more than one answer may be correct. which of the following is a characteristic of unicellular organisms? they can possess tissues and organs. all of their functions are performed by a single cell. they are usually microscopic. each of their cells is specialized to perform a specific function.

Compare and contrast physical changes with chemical changes.

What effect might melting sea ice have for people who live in coastal areas?