Element density refers to the amount of mass per unit volume of an element. It is typically measured in grams per cubic centimeter (g/cm3) for solid elements and in grams per liter (g/L) for gases.
Period 2 of the periodic table includes the elements lithium (Li), beryllium (Be), boron (B), carbon (C), nitrogen (N), oxygen (O), fluorine (F), and neon (Ne).
As you move across Period 2, the element density generally increases. This is because the atomic mass increases and the atomic radius decreases, resulting in a higher mass-to-volume ratio.
The trend in element density within Period 2 is not consistent. While the densities of lithium, beryllium, and boron increase as you move across the period, the densities of carbon, nitrogen, oxygen, fluorine, and neon decrease.
The element density of Period 2 elements is generally lower than those in other periods. This is because the atomic radius tends to increase as you move down a group, resulting in a lower mass-to-volume ratio and lower density.