Question

What is the action of:
(a) Sodium on arsenic
(b) Magnesium on bismuth

Answer 1

Both the s-blocks metals i.e. the sodium and magnesium when reacts with the non-metals of the 15th group belonging to the nitrogen family and comes under the category of p-block elements i.e. arsenic and the bismuth, results in the formation of compounds. Now solve these reactions.

Complete step by step answer:
- First of all, let’s discuss sodium and magnesium first. Both the sodium and magnesium are metals and belong to the s-block elements but sodium is an alkali metal and magnesium is an alkaline earth metal and has the atomic number as 11 and 12 and the mass number as 23 and 24 respectively.
- Sodium metal is very soft and so soft that it could be easily cut with a knife and in its outermost shell it has one electron and has a strong tendency to lose the electron to acquire the stable electronic configuration of the nearest noble gas i.e. the neon. Similarly, magnesium in its outer shell has two electrons and has a strong tendency to lose the electrons to acquire the stable electronic configuration of the nearest noble gas i.e. the neon.
- On the other hand, both the arsenic and bismuth are non-metals and belong to the p-block elements and come under the nitrogen family and have the atomic number as 33 and 83 and the mass number as 74 and 208 respectively.
- Both have five electrons in its valence shell and have a strong tendency to gain the electrons to acquire the stable electronic configuration of the nearest noble gas i.e. the krypton and radon respectively.
Now, considering the statement;
(a) When sodium reacts with arsenic, it results in the formation of compounds i.e. the sodium arsenide. The reaction occurs as:

As \\\ arsenic \\\ \end{matrix}+\begin{matrix} 3Na \\\ sodium\\\ metal\\\ \end{matrix}\to \begin{matrix} N{{a}_{3}}As \\\ \begin{aligned} & sodium\\\ & arsenide \\\ \end{aligned} \\\ \end{matrix}$$ (b) Similarly, when magnesium reacts with bismuth, it results in the formation of compounds i.e. the magnesium bismuthide. The reaction occurs as; $$\begin{matrix} 3Mg \\\ magnesium \\\ \end{matrix}+\begin{matrix} 2Bi \\\ bismuth \\\ \end{matrix}\to \begin{matrix} M{{g}_{3}}B{{i}_{2}} \\\ \begin{aligned} & magnesium \\\ & bismuthide \\\ \end{aligned} \\\ \end{matrix}$$ **Note:** When the metal and the non-metals undergoes reaction , metal atom and the non-metal atom shares electrons with each other to complete their valence and octet and results in the formation of the covalent bond and thus, together forms a compound.