Question

An element 'X' has 16 protons in its nucleus and its mass number is 32. The number of neutrons in its
nucleus and the symbol of its dinegative ion respectively are
(A) 16, X2-
(B) 32, X2+
(C) 32, X2-
(D) 16, X2+​

Answer 1

GiveN :-

• An element 'X' has 16 protons in its nucleus and its mass number is 32 .

To FinD :-

• The number of neutrons in its nucleus and the symbol of its dinegative ion .

SolutioN :-

Given that , there are 16 protons in the nucleus and the mass number of the element is 32. We know that the mass number of a element is given by ,

$\sf\longrightarrow Mass\ number = n(proton) + n(Neutron)$

So that ,

$\sf\longrightarrow 32 = 16 + n(neutrons) \\\\\\\sf\longrightarrow n(neutrons) = 32 - 16 \\\\\\\sf\longrightarrow \boxed{\pink{\frak{ n(neutrons) = 16}}}$

• Also its dinegative ion will be , X²- .

The Element is :- $\sf X^{32}_{16}$

• We know that the number of electrons is equal to the number of protons in a neutral atom . Here the atomic number is 16 . Therefore after gaining two electrons , it will complete its octet .

Hence the correct option is (A) .

Answer 2

Answer:

Given :-

An element 'X' has 16 protons in its nucleus and its mass number is 32 .

To Find :-

The number of neutrons in its nucleus and the symbol of its dinegative ion .

Solution :-

Given that , there are 16 protons in the nucleus and the mass number of the element is 32.

We know that the mass number of a element is given by ,

Mass number = n(proton) + n(neutron)

So that ,

⟶ 32 = 16 + n(neutrons)

⟶ n(neutrons) = 32 - 16

⟶ 32 = 16 + n(neutrons)

⟶ n(neutrons) = 32 − 16

⟶ n(neutrons) = 16

We know that the number of electrons is equal to the number of protons in a neutral atom .

Here the atomic number is 16 .

Therefore after gaining two electrons , it will complete its octet .

Hence the correct option is (A) .