Question

How many electrons should be present in the outermost shell of an atom so that it behaves like a metal?

Answer 1

• Atoms having one to three electrons in their valence shell will lose those electrons and attain stable electronic configuration or octet configuration and behave like metals.
• Example: sodium is an alkali metal with atomic number 11.
• Hence it will have 11 electrons as well. Electronic configuration:2,8,1.
• We can understand that if a sodium atom could lose that one electron in the M shell, it will form a sodium ion (${\mathrm{Na}}^{+}$) with 10 electrons.
• Electronic configuration of thus formed sodium ion;2,8. The L shell is complete with 8 electrons.
• It is easy for a sodium atom to lose 1 electron than to gain 7 electrons to complete the octet.
• Similarly, the second group metals will lose 2 electrons and 13 group elements will lose 3 electrons from their valence shell.