Periodicity

Metalloids, a combination of metal and non-metal properties

Increase in principle energy levels, therefore increase in shielding, outer electron is further from the nucleus.

Decreases as number of protons (nuclear charge) increases, shielding stays constant, electrons are more strongly attracted to the nucleus and atomic radius decreases.

• Repeating trends of physical or chemical properties

Involves the loss of an electron to form a positive ion

• The energy required to remove of 1 mol of electrons from 1 mol of gaseous atoms

Decreases, electron is removed from a higher principle energy level, electron is further from the nucleus, more shielding, weaker attraction between nucleus and outer electron

Increases, number of protons increase, shielding is constant/ atomic radius decreases, stronger attraction between nucleus and outer electron.

Al and S Al - IE decreases, electron is removed from a higher energy p sub-level, weaker attraction between nucleus and outer electron S - IE decreases, pair of electrons in a p-orbital, extra repulsion means less energy required to remove outer electron

• Will always increase, positive charge on ion increases, ionic radius decreases, nuclear attraction on the outer electron increases • Can be used to find an element’s group number (look for the big jump) • The big jump happens when an electron has been removed from a principle energy level that is much closer to the nucleus

Strong electrostatic force of attraction between positive ions and delocalised electrons

• Positive ions repel • Sea of electrons attracted to positive ions

• Ionic charge on metal - stronger=stronger bond • Number of delocalised electrons - more electrons donated to sea the stronger metallic bond • Atomic radius - smaller=stronger

• Good conductors of electricity and heat as delocalised electrons are free to move • Very high m.p and b.p as they have a strong attraction between positive ions and delocalised electrons • Malleable and ductile (can be hammered into shape) - Layers of ions that can slide over each other

• Lithium and Beryllium - metallic bonding - forms a metallic lattice • Carbon - covalent bonding to form giant covalent substance; diamond, graphite or graphene - high m.p and b.p, strong covalent bonds require a lot of energy to break • N2, O2, F2, Ne - non polar molecules, covalent bonding. All have weak London forces

• Diamond - each carbon atom bonded to four other carbon atoms, no delocalised electrons • Graphite - each carbon atom bonded to three other carbon atoms, forming hexagonal layers. Weak London forces between layers, delocalised electrons • Graphene - 1 layer of graphite, delocalised electrons

• Na, Mg, Al - metallic bonding - metallic lattice • Si, giant covalent substance. Each silicon atom bonded to 4 other silicon atoms. Strong covalent bonds require a lot of energy to break. No delocalised electrons • P4, S8, Cl2, Ar - All non polar, weak London forces require little energy to break

• Some of the attractive forces between the particles are broken. Now move more freely around each other but are still close together • The stronger the forces, the more difficult it is to melt

• All the attractive forces between the particles are broken. Free to move more randomly