Chapter 8 Grade 12 SABIS Chemistry Atomic Structure and Periodicity

First ionization energy of sodium causes an Atom Ion( Atom, Ion ) to be changed to an Ion Atom( Ion, Atom )

First ionization energy of sodium causes an electron to be gained lost( gained, lost )

Ionization energy is added removed( added, removed ) as it creates breaks( creates, breaks ) a bond between electron and atom

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

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 2p 2s( 2p, 2s ) orbitals which are closer farther away( closer, farther away ) to the
nucleus, shielded less, so more closely attracted to the nucleus. This makes them
easier harder( easier, harder ) 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 harder easier( harder, easier ) to be removed.

Why is the ionisation energy of sodium less than that of magnesium?
For the same shielding Mg has higher less( higher, less ) 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 3s 3p( 3s, 3p ) electrons is easier than removing 3s 3p( 3s, 3p ) electrons because 3p 3s( 3p, 3s ) are more
energetic.

IE decreases increases( decreases, increases ) down a group

IE decreases increases( decreases, increases ) across a period