Question

The table above shows the number of protons in an Adam of four different elements according to the periodic table which of these elements is a metal

Answer 1

Answer:

The correct answer is X

Explanation:

First have some idea about : Valency , Metals and non- metals.

Valency : It is the combining capacity of elements . The elements combine to other elements to gain stability . They always try to complete their octet(8 electrons in the outermost shell)

For Example : Na has 11 electron

Its electronic configuration is : 2 ,8 ,1 (2+8+1 = 11)

First shell contain maximum = 2 electron

2nd shell = maximum 8 electron

3 shell = maximum 18 electron

When it remove 1 electron from outermost shell , it is left with 2 ,8 configuration. Now , its outer most shell has 8 electron . so it get stable and show +1 valency.

When the element looses electron , it get positive charge

When the element gain electron it get negative charge

Metals: those element which show +1 , +2 , +3 valency are considered as metals

Non- metals = Those metals which show the valency of -1 , -2 ,-3 are considered as Non- Metals.

Questions:

1. T = 7 proton

Electronic configuration = 2 , 5

It gains (-ve charge) 3 electron to achieve complete octet(5+3 = 8) = -3 valency

It is non- metal

2. Q=15

Its electronic configuration = 2 ,8 , 5

It gains (-ve charge) 3 electron to achieve complete octet(5+3 = 8) = -3 valency

It is non- metal

3.X = 12

Its electronic configuration = 2 ,8 , 2

It loses (+ve charge) 2 electron to achieve complete octet( 2 , 8) = + 2 valency

It is  metal

4.Z = 17

Its electronic configuration = 2 ,8 , 7

It gains (-ve charge) 1 electron to achieve complete octet(7+1 = 8) = -1 valency

It is non- metal

There is only one metal = X