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

Number of protons +Number of neutrons = mass number = 81
Let the number of protons = x Number of neutrons = x131.7/100 = 1.317x X+1.317x = 81 X = 35
So, atomic number = 35 Element with atomic number 35 =Br

Hello Student
Number of protons +Number of neutrons = mass number = 81
Let the number of protons = x
Number of neutrons = x131.7/100 = 1.317x
X+1.317x = 81
X = 35
So, atomic number = 35
Element with atomic number 35 =Br

Hi,studentLet,the mass of an element is xX=e-X=X*,31.7\100+XSo,we can write X+,X+31.7x/100=81100x+100x+31.7x/100=81200x+31.7x=,8100231.70x,=8100*100/231.70X=8100/2317X=34.9=35We know Br`,s atomic number=35