Why do the metals on the periodic table have a +charge

Because of the loss of electrons.

Explanation:

For example in a Sodium atom, the electronic configuration is 2,8,1 as it is 11 in total. In order to make the atom stable, it needs to lose one electron which makes the outer shell contain the maximum electrons it should have it an atom has more than one shell. Hence, if an atom loses an electron, it will gain a + charge.

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the answer is 303.15 or 303