The mass of Mg-24 is 24.30506 amu, it contains 12 protons and 12 neutrons.
Theoretical mass of Mg-24:
The theoretical mass of Mg-24 is:
Hydrogen atom mass = 12 × 1.00728 amu = 12.0874 amu
Neutron mass = 12 x 1.008665 amu = 12.104 amu
Theoretical mass = Hydrogen atom mass + Neutron mass = 24.1913 amu
Note that the mass defect is:
Mass defect = Actual mass - Theoretical mass : 24.30506 amu- 24.1913 amu= 0.11376 amu
Calculating the binding energy per nucleon:

So approximately 4.41294 Mev/necleon
Refraction
the fact or phenomenon of light, radio waves, etc. being deflected in passing obliquely through the interface between one medium and another or through a medium of varying density.
: the force that is necessary to keep an object moving in a curved path and that is directed inward toward the center of rotation a string on the end of which a stone is whirled about exerts centripetal<span> force on the stone — compare centrifugal force.</span>