Question

The binding energy of an electron to a proton (i.e., hydrogen atom) is 13.6 eV. The loss of mass in the formation of one atom of hydrogen is _____________

(a) 2.42 X 10^-35 Kg

(b) 3.34 X 10^-35 Kg

(c) 4.58 X 10^-35 Kg

(d) 5.19 X 10^-35 Kg

The question was asked by my school teacher while I was bunking the class.

My question comes from Mass Energy Relation in division Ultrasonics & Relativity of Engineering Physics I

Answer 1

Right answer is (a) 2.42 X 10^-35 Kg

The best I can explain: E = 13.6 eV = 13.6 X 1.6 X 10^-19 J

Using Einstein’s Mass-energy relation, the loss of mass Δm = E/c^2

Δm = 13.6 X 1.6 X 10^-19/9 X 10^16

= 2.42 X 10^-35 Kg.