The scientist who discovered carbon dioxide gas​

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

Iwould appreciate if someone could me.

Phosphorous can form an ion called phosphide, which has the formula p3−. this ion can form an ion called phosphide, which has the formula p3−. this ion properties very similar to those of pforms when a phosphorus atom loses three protonsis called a cationcontains 18 electrons