Question

If the mass of neutrons is doubled & mass of an electron is halved then find out the new atomic mass of ${}_6{C}^{12}.$ and the percent by which it is increased?

Answer 1

${}_6{C}^{12}\to e=6$

Number of protons = $6=6amu$

Number of neutrons = $6=6amu$

Total mass = $(6+6)=12amu$

Mass of the electron is negligible.

If the mass of the neutron is doubled, then the total mass = $(6\times 2)+6=$ $18amu$

Therefore, the % of the increase = $=\frac{18-12}{12}\times 100=50\%$