Question

Elements $$\mathrm{X},\mathrm{Y}$$ and $$\mathrm{Z}$$ have 4, 5 and 7 valence electrons respectively. Write the molecular formula of the compounds formed by these elements individually with hydrogen.

Answer 1

To the electronic configuration, a total of 8 electrons must be present in the valence shell of an element. Element $$\mathrm{X}$$ has 4 valence electrons, so it will share the remaining 4 electrons for the formation of the bond, the molecular formula will be $$\mathrm{XH}{\phantom{A}}_4$$. The element $$\mathrm{Y}$$ has 5 valence shell electrons, so it will form 3 bonds and the formula will be $$\mathrm{YH}{\phantom{A}}_3$$. The element $$\mathrm{Z}$$ has 7 valence shell electrons, so it will form one bond with hydrogen and has the molecular formula $$\mathrm{H}-\mathrm{Z}$$.