# Periodic and Aperiodic Properties (continued)

Specific density or mass is the relationship between the mass (m) of a substance and the volume (V) occupied by that mass.

This variation in solid state is a periodic property. In the periodic table, density values ​​increase in families from top to bottom and, in periods, from ends to center.

Thus, it can be noted that the densest elements are in the center and bottom of the periodic table.

Examples:
- Os (os) - d = 22.5g / mL
- Ir (iridium) - d = 22.4g / mL

Melting point is the temperature at which matter passes from the solid phase to the liquid phase.

Boiling point is the temperature at which matter passes from the liquid to the gas phase.

In the periodic table the values ​​of PF and PE vary, in one family to the left of the table increases from bottom to top, and to the right of the table increases from top to bottom. In periods, it increases from the ends to the center.

In the periodic table, there are elements of different physical states.

- gas phase: H, N, O, F, Cl, Ne, Ar, Kr, Xe, RN
- liquid phase: Hg and Br
- solid phase: other elements

Imagine the elements:

X = solid phase
Y = liquid phase
Z = gas phase

So we have:

X with PF and PE greater than Y and Y with PF and PE greater than Z

Carbon (C) is an exception to this rule. It has an MP of 3800 ° C.

Tungsten (W) is the highest PF metal at 3422 ° C and is used in filament incandescent lamps.

It is the minimum energy required to "pull out" an electron from an isolated atom in its gaseous state.

The first ionization potential is considered the most important because it is the energy required to "pull out" the first electron from the outermost layer of the atom.

According to SI (International System) it must be expressed in Kj / mol.

Ionization potential is a periodic property, which in the periodic table behaves exactly the opposite of the atomic radius.

The larger the atomic radius, the lower the attraction of the nucleus with its farther electron. So it's easier to "rip out" the electron. Consequently the ionization energy is lower.

The ionization potential increases in families from bottom to top and, in periods, from left to right.