Number 18 is correct, number 19 is the particles speed up and the substance expands, and number 20 is decrease in volume
The gasses around the earth or any planet
In an automobile engine, fuel is burned to convert chemical energy into __ energy. This energy is then changed into __ energy.
1 ) Heat
2 ) Mechanical
"In an automobile engine, fuel is burned to convert chemical energy into "heat" energy. This energy is then changed into "mechanical" energy"
(Goes from Chemical energy, heat energy, to mechanical energy.)
