periodicity

Question 1

factors effecting atomic radius

Answer 1

nuclear attraction (r decreases along period)
electron shielding (r increases down a group)

Question 2

ionic radius (trends and def)

Answer 2

smaller compared to atomic for metals (losing e- and a shell)
larger compared to non metals (nuclear charge is constant, but average ,,force’’ decreases due to being applied onto more e-)

Question 3

1st ionisation energy (definition)

Answer 3

energy required to remove {one electron from each atom} in {1 mole} of {gaseous atoms}

Question 4

factors effecting 1st ionisation energy

Answer 4

atomic radius
nuclear charge/attraction
electron shielding

Question 5

along period 3, why is there a decrease in 1st ionisation energy in Al and then S

Answer 5

Al - 3p orbital starts to fill up, which is further from the nucleus, so easier to remove electrons
S - 3p orbitals start filling with 2 e-, which repel each other, making it easier to remove one

Question 6

2nd ionisation energy

Answer 6

energy required to (remove 1 e- )from( each ion) in (1 mol. of gaseous ions)

Question 7

ionisation energy of Mn compared to Cr
(Cr -> Mn on PT)

Answer 7

1st IE of Cr < Mn
2nd IE of Cr > Mn
(Cr⁺ has a stable half-filled configuration)
3rd IE of Cr < Mn
(stable configuration of the Mn²⁺ ion)

Question 8

Trend in ionisation energy down a group

Answer 8

Decreases:
Although nuclear charge ^
atomic radius/electron shielding ^ (another e- shell)
more significant, so less energy to remove valence electron