Chapter 8 Grade 12 SABIS Chemistry Atomic Structure and Periodicity

First ionization energy of sodium causes an [blank_start]......[blank_end] to be changed to an [blank_start].......[blank_end]

First ionization energy of sodium causes an electron to be [blank_start]gained[blank_end]

Ionization energy is [blank_start]added[blank_end] as it [blank_start]creates[blank_end] a bond between electron and atom

Write equations to illustrate the first and second ionisation energies of sodium. Na([blank_start]g[blank_end]) --> Na[blank_start]+[blank_end](g) + [blank_start]1 e-[blank_end] Na+([blank_start]g[blank_end])--> Na[blank_start]2[blank_end]+(g) + [blank_start]1e-[blank_end]

Explain why the second ionization energy of any atom is always larger than its first The 1st e- is being removed from a [blank_start]neutral atom[blank_end] whereas the second electron is being removed from a [blank_start]+1 ion[blank_end], the same nuclear charge is attracting a smaller number of electrons, so the electrons are held [blank_start]more firmly[blank_end].

The second ionisation energy of sodium is around 9 times larger than its first, while the third is only around 1.5 times larger than its second. Suggest why this is so. The electron being removed from Na+ is from [blank_start]2p[blank_end] orbitals which are [blank_start]closer[blank_end] to the nucleus, shielded less, so more closely attracted to the nucleus. This makes them [blank_start]harder[blank_end] to be removed. The electron being removed from Na+2 is also from 2p orbitals which are relatively the same distance from the nucleus, same shielding, so attracted to the nucleus slightly more. This makes them only a little [blank_start]harder[blank_end] to be removed.

Na is larger ⇒more [blank_start]shielding[blank_end] The electron being removed in Li is the [blank_start]2s[blank_end] and the electron being removed in Na is the [blank_start]3s[blank_end]. The electron in 3s is [blank_start]further away[blank_end] from the nucleus

Why is the ionisation energy of sodium less than that of magnesium? For the same shielding Mg has [blank_start]higher[blank_end] nuclear charge.

Why is the ionisation energy of aluminium less than that of magnesium? Al: 1s2 2s2 2p6 3s23p1 Mg: 1s2 2s2 2p6 3s2 Removing [blank_start]3p[blank_end] electrons is easier than removing [blank_start]3s[blank_end] electrons because [blank_start]3p[blank_end] are more energetic.

IE [blank_start]decreases[blank_end] down a group

IE [blank_start]increases[blank_end] across a period