1) how does an atom become a negative ion?
2)how does an atom become a positive ion?
2007-03-19 17:55:42 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
An atom becomes a negative ion when it accepts an electron. The most desirable stage for any atom of any element in periodic table is when their outermost electron shell (valance) has 8 electrons (or in other worlds is completely full of electrons). Atoms of group 8 (noble gases) have a full valence; meaning they have no more room for any extra electron (that is why they don't react with other atoms).
To complete a valance shell, an atom has to receive or loose enough electron until its valence has 8 electrons (or in case of hydrogen, until it has no electrons). Atoms of groups 4 to 7 need 4 to 1 electrons to complete their outermost shells. therefore these atoms adept electrons from atoms of other elements. Therefore their electric charge becomes negative so they become negative ions.
Atoms of groups 1 to 3 (ans transitional metals) have between 1 to 3 electrons in their valence shell, therefore it is easier for them to loose their electrons and become positive ions.
2007-03-19 18:17:53 · answer #1 · answered by smarties 6 · 1⤊ 0⤋
1)...By gaining one or more electrons.
2)...By losing one or more electrons.
2007-03-20 01:04:01 · answer #2 · answered by Norrie 7 · 1⤊ 0⤋