CE Chemistry I

The statement is true only for the metals with small atomic numbers (e.g. metals in Periods 2 and 3 of the Periodic Table such as Al and Ca). For those metals, the numbers of electrons in the outermost shells are always less than 4.

However, the statement is false for metals with large atomic numbers.
For example, tin (錫) and lead (鉛) are Group IV elements and they are metals. Both of them have 4 electrons in the outermost shell of their atoms.
Furthermore, bismuth (鉍) is a Group V element and it is a metal. The atom of bismuth has 5 electrons in the outermost shell.

Conclusively, the statement is true for metals with small atomic numbers, but it is false for metals with large atomic numbers.

actually , the structure of metal is that the positively charged nuclei
are surrounded by negatively charged electrons.the outermost
shell electrons are delocalised which accounts for the
conduction of electricity.