All atoms of isotopes of a particular element have the same number of protons, but different numbers of neutrons in their nuclei.
true
false

True

Explanation:

All isotopes have equal number of protons but differ by number of neutrons in the nucleus. The number of neutrons changes the weight of the elements, but not the atomic number since that is a function of protons. Most isotopes are radioactive and are not stable. Eg C has two isotopes ¹²C and ¹³C, they only varies by number of neutrons and still have the same type of chemical reactivity. But ¹²C is found in nature while ¹³C is radioactive and used in carbon dating.

i believe the answer is three water molecules