All atoms of the same element have the same number of which is called the atomic number.
a. electrons
b. protons and neutrons
c. neutrons
d. protons

The correct answer is "d".

Explanation:

Hello! All atoms of the same element have the same number of protons. The atomic number is the amount of protons that the element has. This is usually represented by the letter Z. Different elements have different numbers of protons.

So the correct answer is "d".

c is the answer because when something is left after something evaporates that shows the chemical change.