Question

Why is that metal form positive ion and
metal form negative ions ?​

Answer 1

Explanation:

Ionic bonds form only between metals and nonmetals. That's because metals “want” to give up electrons, and nonmetals “want” to gain electrons. It takes energy to remove valence electrons from an atom and form a positive ion. Energy is released when an atom gains valence electrons and forms a negative ion.

Answer 2

Answer:

Metals are very electropositive, meaning that their outer electrons are very loosely bound to them, so that that electronegative atoms (atoms which tend to suck-in electrons) react with metals to form ionic compounds consisting of negative ions of the electronegative element, and positive ions of the metal.