Chemical properties of atoms relies solely on the number of electrons they contain, more particularly, the valence or outermost electrons in the orbit round the nucleus of an atom.
A neutral atom is one that has not gained or lost electron or even shared electrons with any other atom.
On close examination of how electrons are distributed in the orbits of an atom, we can know if an atom will gain or lose electrons in a reaction. This is very important in determining the chemical properties of an atom.
Mendeleev has tried to organize the chemical elements in the periodic table according to their atomic weights, as they differ if their weight increase.
The elements have been arranged in such a way that their the number of electrons in the outermost shell depicts its properties.
The neutral atoms have their outermost shell filled with electrons. They have noble gas configuration which means they are non reactive and will not take part in any of the reactions.
Example Argon, which has 18 electrons, is a noble gas and has 8 electrons in the outermost shell.
