Hydrogen has three isotopes 1h 2h 3h what is the diffrence

Isotopes indicate the different number of neutrons in the atom the periodic table will always show the number of protons and total mass. If the mas is one gram more then there is one more neutron. 1H is abnormal hydrogen atom without any added neutrons. 2H has one more neutron then usually, and etc.

It won't lose or gain electrons if it's a covalent bond it shares the electrons with another atom or atoms. if it is an ionic bond it will lose the 3 electrons on the outer shell and become a positively charged ion.  credit goes to @sunshinebaby of answers.yahoo.com.