What is acceleration?
a. change in velocity/change in time
b. change in distance/change in time
c. change in mass/change in volume
d. change in pressure/change in time

This is what a calorimeter is used for simpler ex, to measure calories in food.

The answer is d, you can easily test a theory! hope i you : )

In atoms, the electron carries a negative elementary or unit charge; the proton carries a positive charge. the two types of charge are equal and opposite. in an atom of matter, an electrical charge occurs whenever the number of protons in the nucleus differs from the number of electrons surrounding that nucleus.