Periodictiy

Seite 1

The Periodic Table shows all the elements in order of increasing atomic number.

Metals are found on the left of the "staircase line" and non-metals on the right.

The elements that have their highest energy electrons in an s-orbitals are in the

s-block. There's also the p-block, the d-block and the f-block.

The transition metals and d-block elements are not the same - zinc and scandium are not transition metals because they don't form compounds in which they have partially filled d-orbitals.

A group is a vertical column of elements. Elements in the same group form a chemical "family". They are numbered 1-8 or 1-18 including the transition metals.

Seite 2

The melting and boiling points increase from sodium to aluminium because of the strength of metallic bonding. As you go from left to right, the charge on the ion increases so more electrons join the delocalised electron sea.

The melting points of the non-metals depends on the size of the van der Waal forces, which in turn depend upon the amount of electrons in the molecule.

The atomic radius decreases as you go across a period. This is because there is a stronger atomic attraction as the amount of protons increase without there being more shielding as the electrons don't go into a new shell.

As you go down a group, the atomic radius increases as there are more electrons.

The first ionisation energy generally increases across a period due to there being more protons and the electrons entering the same main level so it is harder to remove an electron. It decreases down a group as there is more shielding and the outer electrons are further from the nucleus so there is less attraction.

However, between Group 2 and 3 and Group 5 and 6, it decreases. This is because the outer electron is in a new shell, so there is more shielding, and takes less energy to remove.