Question

The electronic configuration of an element x is 2 8 6 .To whichgroup and period of the modern periodic table does x belong .Stste the valency and justify your answer in each case

Answer 1

Answer: X belongs to group 16 and period 3

Justification: According to Mendeleev's periodic table, number of shells define the period in which the element belong to and number of valence electrons define the group but if an element have electrons in outermost shell more than two, ten is added to its electrons in the outermost shell.

For example if an element have electronic configuration 2,8,3 then its group is 3 (as number of shells define group) and its valency is 3+10= 13 ( because if outermost shell have electrons more than two, ten is added to its electrons in outermost shell).

Hope this helped!!:-)

Answer 2

Answer:

1 . Since ‘X’ has three energy shells and period number of an element is equal to the number  of energy shells, X belongs to 3rd period.

2 . X has 6 valence electrons it belongs to group 16.

3.  Valency will be 2. To acquire noble gas configuration it will gain 2 electrons.