Question

the atomic number of an element x is 15 identify it's position in term of group and period in modern period table​

Answer 1

The electronic configuration of element is X

K L M

2 , 8 , 5

Since , there are 3 Orbits hence the period is 3.

Now, the valence electrons in the element X is = 5

Hence , the group no. is ( 10+5 ) = 15

Therefore , the element belongs to GROUP 15 and PERIOD 3 .

That is the element X is Phosphorus.

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Another way is S P D F configuration of element X

1s^2 2s^2 2p^6 3s^2 3p^3

From this it is clear that the element is of P-block and of 3rd period with 3 valence electrons.

No. subtract the no. of valence electrons from 8 , and add 10

You will get the group no. = 10 + ( 8-3) = 15

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Hope it helps ! :)

Answer 2

grop is 15

period 3

element x is phosporus