Consider the following elements: _ 20 Ca , 8 O , 18 Ar , _ 16 S, … - Vidyadip

Question

Consider the following elements:
${ }_{20} Ca , 8 O , 18 Ar ,{ }_{16} S, 4 Be , 2 He$.
Which of the above elements would you expect to be:

Very stable?
In group 2 of the periodic table?
In group 16 of the periodic table?

✓

Answer

i. 18 Ar and ${ }_2 He$ (Noble gases).
ii. ${ }_{20} Ca$ and ${ }_4 Be$ (no. of valence electrons in each $=2$ ).
iii. 8 O and ${ }_{16} S$ (no. of valence electrons in each $=6$ ).

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