An atom of lithium-7 has an equal number of

(1) electrons and neutrons

(2) electrons and protons

(3) positrons and neutrons

(4) positrons and protons

The answer is (2). The Lithium has 3 protons and 4 neutrons. For every neutral atom, it will have the same number of protons and electrons. Because the proton has one positive charge and electron has one negative charge and neutron does not have charge.