Taking the example of an element of atomic number 16, explain how the electronic configuration of the atom of an element relates to its position in the modem periodic table and how valency of an element is calculated on the basis of its atomic number.(All India - 2015)
Answers
Explaination about given element is written below-
According to question, element has atomic number 16. Thus, according to octet rule, electronic configuration of element will be - 2,8,6.
The electronic configuration conveys the information that there are three shells in element, hence it will be placed in period 3.
Outermost shell has 6 electrons and therefore element belongs to group 16.
To calculate valency, number of electrons in outermost shell will be counted. In general, if an element has electrons in outermost shell ranging from 1 to 4, the number will be it's valency.
If number of electrons exceed 4, then valency will be calculated as follows -
8 - number of electrons in outermost shell.
Since given element has 6 electrons in outermost shell, then according to given method, valency will be 2.
This means, element requires two electrons to complete it's octet.
The element with atomic number 16 is sulphur.