Group 2 and group 7 metals

Period 3

Melting and boiling points – The ones with high melting points are on the left, with sodium the exception. The ones on the right are low melting points.

Giant structures have high melting points (on the left)

Molecular structures (on the right) have low melting points.

Mp’s and bp’s from Na to Al increase because of the strength of metallic bonding. As you go from left to right the ion charge increases so more electrons join the delocalised electron ‘sea’ that holds the giant metallic lattice together.

Silicon has a giant structure so it has a higher melting point.

Atomic radii – Atomic radius is a periodic property because it decreases across each period and there is a jump when you start the next period.

Atom size decreases because the nuclear charge increases and the increased charge pulls the electrons in closer to the nucleus. No additional shells to provide more shielding. Atom size decreases

Atoms get larger as you go down any group.

First ionisation energy is the energy required to convert one mole of isolated gaseous atoms into a mole of singly positively charged ions.

Increases ACROSS a period. The number…