Which of the following are correct descriptions of heat flow? check all that apply. a. conduction is heat flowing when a liquid or gas carries the heat. b. radiation is heat flowing in waves. c. conduction is heat flowing between two objects that are touching each other. d. convection is heat flowing between two objects that are touching each other.

The correct options are:
B.Radiation is heat flowing in waves.
C.Conduction is heat flowing between two objects that are touching each other.

In fact, radiation is heat transferred by electromagnetic waves, while conduction is the heat transfer between touching objects (the particles of one object collide with the particle of the other object, and so heat is transferred via the transfer of kinetic energy between the molecules).

Instead, option A is wrong (because conduction is the heat transfer between touching objects) and option D is wrong because convection is the heat flowing when a liquid or a gas carries the heat.