8.
Energy traveled through waves, speaker
10.
Light, electromagnetic waves from sun
12.
Heat transfer through direct contact
13.
Heat transfer through electromagnetic waves
14.
Heat transfer through fluids
15.
Part that is being studied
16.
Everything outside the system
17.
Energy cannot be created or destroyed
18.
Movement of thermal energy
19.
Two objects touching reaching the same temperature
20.
Measure of how hot or cold something is
21.
Small piece of matter, atom or molecule
