Solid magnesium sulfide has the same kind of crystal structure as NaCl which is pictured below: If the edge length of the unit cell is 519.0 pm, what is the density of MgS in g/cm3.

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.

b) nuclear ive learned that in a pedtrodic table