What happens when atoms from group IA combine with atoms from group VII?

1 Answer
May 20, 2017

see below


I'll assume you mean group VII A. In general, when a metal from group IA (ionic charge #1+#) forms a bond with a nonmetal from group VIIA (ionic charge #1-#), there will be a #1:1# ratio of the atoms in one formula unit of the compound. The metal will give up its lone outer-shell electron and nearly completely transfer it to the halogen so that both atoms achieve an octet of valence electrons.

For example, when a atom of potassium (#K#) bonds with an iodine (#I#) atom, the resulting compound is #KI# (potassium iodide), and it results when the potassium atom donates its lone electron in its #4s# subshell to iodine, which only needs one more electron to fill its valence shell.