The atom which it would be most difficult to remove an electron from is: an atom of a noble gas.
An atom refers to a smallest, indivisible unit that comprises the matter that forms all chemical elements.
Basically, the three (3) distinct particles that makes up an atom include;
Protons.Neutrons.Electrons.
Electrons are the subatomic particles of a chemical element that are negatively charged with a magnitude of -1.
Noble gases can be defined as a group of chemical elements with eight (8) valence electrons, which simply means they are found in group eight (8) of the periodic table and have a full octet.
Some examples of noble gases are:
Argon.Neon.Krypton.Helium.Xenon.
The octet rule states that atoms of chemical elements lose, gain or share electrons, in order to have eight (8) electrons in their valence shell.
Based on the octet rule, it would be most difficult to remove an electron from the atom of a noble gas because of its high ionization energy and a completely filled valence (outermost) shell.
In conclusion, the full octet possessed by noble gases make them unlikely to combine with other chemical elements.
Read more: link
