Which statement about nitrogen atoms is false and why? They all have 7 protons; they all have 7

neutrons; they have an atomic mass equal to the number of protons and neutrons; nitrogen has

an atomic number of 7.

They all have seven neutrons is false statement.

Explanation:

An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.

All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.

The isotopes of an atom have different atomic masses because of different number of neutrons.

The atomic number of nitrogen is 7. It has seven protons and seven electrons.

The isotope of nitrogen N¹⁴ has seven neutrons and seven protons. Its mass is 14 amu.

The isotope of nitrogen N¹⁵ has eight neutrons and seven protons. That's why its mass is 15 amu.