Structure 3

Question 1

Element Groups

Answer 1

• Alkali metals
• Alkali earth metals
• Boron group
• Carbon group (crystallogens)
• Nitrogen group (pnictogens)
• Oxygen group (chalcogens)
• Fluorine group (halogens)
• Noble gases

Question 2

Physical Properties

Answer 2

• Atomic/ionic radii
• Ionization energy
• Electronegativity
• Electron Affinity
• Melting/boiling pts.

Question 3

Chemical properties

Answer 3

• Chemical bonding
• Coordination Number
• Acidity/Basicity of oxides
• Flammability
• Reactivity

Question 4

Atomic Radius

Answer 4

• Increases down group because (more electrons) which are added to a (higher energy level) - making it (further from nucleus).
• Decreases across period because electrons are added to (same energy level), thus same (shielding constant), but the (number of protons/nuclear effective charge also increases) - (attracting electrons) to the nucleus.

Question 5

Ionic Radii

Answer 5

• Cations smaller than parent atoms due to (losing electrons), (decreasing the number of energy levels). Because the (number of protons is greater than the number of electrons), the electrostatic attraction of electrons towards the nucleus also increases.
• Anions larger than parent atoms due to (gaining electrons, (increasing electron repulsion).
• Across a period, ions have the same number of electrons (isoelectronic) but (increasing Zeff) so (ionic radius decreases).

Question 6

Ionization energy

Answer 6

• Generally increases across period due to (greater nuclear effective charge) and (same shielding constant).
• Decreases down group due to (larger atomic radius) and (greater shielding constant) - outweighing the greater nuclear effective charge.

— Discontinuities occur between sub-levels —
- p has a (higher energy) and thus (further away from nucleus) than s - therefore (slight decrease in 1st IE).
- (slight decrease in 1st IE) between orbitals [2p3, 2p4] due to (spin pair repulsion) in 2p

Question 7

Melting/boiling pts.

Answer 7

• Decreases down group 1 (alkali metals) because (more energy levels & larger atomic radius) making (valence electrons easier to remove).
• Increases down group 18 (halogens) because (more electrons & larger molecular size) making (intermolecular forces stronger)

Question 8

Reactivity

Answer 8

• Increases down group 1 (alkali metals) because (larger atomic radius).
• Decreases down group 18 (halogens) because (stronger intermolecular forces).