Calculate the energy released when isotope of carbon, 146c , decays by β− emission. the atomic mass of 146c is 14.003242 u , the atomic mass of 147n is 14.003074 u . assume that the neutrino has no mass.

The correct answer is: 156.49 keV (0.15649MeV)

Explanation:
Since 

E = mc^2

Where E = Energy = ?
m = mass = (14.003242 - 14.003074) amu = 1.68*10^-4amu

Also 1amu * c^2 = 931.5 MeV

Plug in the values in the equation:
E = (1.68*10^-4)*(931.5 MeV) = 0.15649 MeV = 156.49 keV

C. 1s22s22p63s23p43d104s24p5

Non metal is an element or substance that is not a metal metal is a solid material that is typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivitymetalloid is an element (e.g., germanium or silicon) whose properties are intermediate between those of metals and solid nonmetals. they are electrical semiconductors.