More Group Seven Metals ... Again

Just so I really get the hang of it. (:

The Halogens are diatomic molecules: F2, Cl2, Br2, I2... At2

At room temperature, Fluorine => Pale yellow gas.
Chlorine => Greenish gas.
Bromine => Red-brown liquid
Iodene => Black solid.

The size of atoms increase as you go down the group, because as you go down the group, you go down a period, which means each has one more shell of electrons then the next, making the atomic radius larger. (As you go down the group.)

Electronegativity: is the ability an atom has to pull electrons towards itself within a covalent bond. The trend is that as you go down the group, it gets less electronegative. This is because as you go down the group you get one more outer shell, as you go down a period, and this means the distance between the outer shell and the nucleus is further, and also, there are more electrons as you go down the group, and this means there is more shielding, making the electrostatic forces lower, and therefore, a lower electronegativity as you go down the group.

The melting point increases as you go down the group, as there are more electrons as you go down the group, and therefore, great Van Der Waals forces holding the compound together. The melting point relies on the energy you need to put in to break the bonds and with stonger bonds, you need to put in more energy to break them. And therefore, the melting point will be higher.

Astetine would be expected to be darker and denser then all of the others in the group.