Question

Which of the following configuration represents a metal:

• A. $1s^{2}2s^{2}2p^5$
• B. $1s^{2}2s^2$
• C. $1s^2$
• D. Both $\left(b\right)$ and $\left(c\right)$

Answer 1

The correct option is B $1s^{2}2s^2$

Metals are those which can easily loose its valance electrons to attain nearest noble gas configuration. In $1s^{2}2s^2$, it can easily loose two electons to attain noble gas configuration. Therefore $1s^{2}2s^2$ represents the configuration of a metal.

Whereas $1s^{2}2s^{2}2p^5$ is the configuration of a non-metal as it has the tendency to gain an electron and attain a noble configuration.

Similarly $1s^2$ is the configuration of Helium gas which is a noble gas and which is a non-metal due to no tendency to lose electrons.