The atomic number of an element ‘X’ is 20. Write (a) its valency, (b) whether it is a … of atomic number 8. Justify your answer…
Answers:
The electronic configuration of X is 2,8,8,2
Since it has 2 valence electrons in its valence shell and it will lose 2 electrons to gain nearest stable gas configuration. So, the valency of X is 2.
(b) Since it loses electrons to gain inert gas configuration, so it is a non-metal.
(c) Atomic no. of element Y is 8
Electronic configuration will be 2,6
Valency of Y will be 2
The formula of compound can be calculated by crossmultiplying the valences as follows:
Therefore, formula is XY.