Question

An ion with mass number 81 contains 31.7% more neutrons as compared to proton. Assign the atomic symbol.

Answer 1

Let the number of protons in the element be x. ∴ Number of neutrons in the element 
= x + 31.7% of x 
= x + 0.317 x 
= 1.317 x 
According to the question, 
Mass number of the element = 81 
∴ (Number of protons + number of neutrons) = 81 

Hence, the number of protons in the element i.e., x is 35. 
Since the atomic number of an atom is defined as the number of protons present in its nucleus, the atomic number of the given element is 35. 
∴ The atomic symbol of the element is 

Answer 2

Answer:

Let the number of protons in the element be x. ∴ Number of neutrons in the element 

= x + 31.7% of x 

= x + 0.317 x 

= 1.317 x 

According to the question, 

Mass number of the element = 81 

∴ (Number of protons + number of neutrons) = 81 

Hence, the number of protons in the element i.e., x is 35. 

Since the atomic number of an atom is defined as the number of protons present in its nucleus, the atomic number of the given element is 35. 

∴ The atomic symbol of the element is

Explanation: