Topic 3 - Periodicity

3.1.1 - Distinguish between the terms group and period

Group - a column in the table eg. Group 1 - Na --> Fr

Period - a row across the table eg. Period 3 - Na --> Ar

3.2.1 Describe first ionization energy and electronegativity

First ionization energy - the energy needed to remove 1mol of electrons from one mole of gaseous atoms

Electronegativity - the ability of an atom to attract electrons in a covalent bond 

3.2.2 Describe and explain the trends in atomic and ionic radii, first ionization energies, electronegativities and melting points for the alkali metals and the halogens

Atomic and ionic radii:- Alkali metals - increases down the group

                                         Halogens - increases down the group

1st IE:- Alkali metals - decreases down the group

             Halogens - decreases down the group

Electronegativities:- Alkali metals - decreases down the group

                                     Halogens - decreases down the group

Melting point:- Alkali metals - decreases down the group

                          Halogens - increases down the group