Question

In the elements of the third period : Na , Mg, Al, Si, P, S, Cl and Ar, Choose metals

Answer 1

• Metals are electron donors, they generally have 1,2 or 3 electrons In their outermost shell.
• Similarly non-metals are electron acceptors, they generally have 5,6 or 7 electrons in their outermost shell. And semi metals on the other hand generally have 4 electrons in their valance shell.
• Electronic configuration for set of elements given in the question would be

$$\begin{gathered} {}_{11}Na\to 2,8,1 \\ {}_{12}Mg\to 2,8,2 \\ {}_{13}Al\to 2,8,3 \\ {}_{14}Si\to 2,8,4 \end{gathered}$$

$$\begin{gathered} {}_{15}P\to 2,8,5 \\ {}_{16}S\to 2,8,6 \\ {}_{17}Cl\to 2,8,7 \end{gathered}$$

Hence here Sodium (Na), Magnesium (Mg) and Aluminum (Al) has 1, 2 and 3 electrons in their valance shell respectively, so they will tend to loose electrons so they are metals.