Bonds and electrons
Only ionic bond involves removal of electron from an atom. The element which donates the electron has positively charged nucleus which then reacts with negatively charged particles around them.
(e.g.) Rust formation on any iron utensils and tools exposed to water and cold air.
Presence of water as a medium enables iron to be ionized to
In co-valent bond compounds the electron is not removed from the nucleus but is shared with between the reacting atoms. (e.g.) Methane. Carbon shares one electron with all hydrogen atoms.
In co-ordinate bond one or more pairs of electrons is donated from a ligand to an atom which generally is a metal. (e.g) Haemoglobin.