1 - atomic structure & periodic table

Question 1

(3)

factors affecting ionisation energy

Answer 1

• nuclear charge - atoms w more protons have stronger postive charge, more electrostatic attraction
• atomic radius - electrostatic attraction ↓ w distance, electrons in smaller atoms are closer to nucleus, ↑ electrostatic attraction
• electron shielding - inner e shells shield outermost e’s from the full attractive force of nucleus, ↓ the charge, more e’s → more shielding

Question 2

(3)

why does ionisation energy ↓ down a group

Answer 2

• nuclear charge - increases ↓ group, more protons, ↑ attraction for electrons
• atomic radius - ↑ down group ∵ more e shells added, moving e’s away from the nucleus
• electron shielding - ↑ down group as more inner e shells reduce nuclear attraction

Question 3

(3)

why does ionisation energy ↑ across a period

Answer 3

• nuclear charge - ↑ as more protons are added
• atomic radius - ↓ as extra electrons added to the same shell
• electron shielding - stays similar across periods with no extra inner shells

Question 4

(4)

why is there a drop in ionisation energy between group 2 and 3

Answer 4

• in g3 the electron is removed from a p orbital, not an s
• p orbitals have slightly ↑ energy than s ∴ outermost e is further from nucleus
• p orbital has additional shielding from nucleus provided by s electrons
• less energy is needed to remove the outermost p electron from g3 element

Question 5

(4)

why is there a drop in ionisation energy between group 5 and 6

Answer 5

• in g5 electron is removed from a singly occupied orbital
• in g6 electron is removed from an orbital w 2 electrons
• the paired e’s in g6 element experience greater electron-electron repulsion
• less energy needed to remove one of the paired e’s in g6 element

Question 6

(3)

do successive ionisation energies increase or decrease within the same shell?

Answer 6

• increase
• succesive e’s are removed ∴ remaining electrons experience electrostatic attraction to positive nucleus
• increased nuclear attraction requires more energy to remove next electron

Question 7

relative isotopic mass

Answer 7

mass of one atom of an isotope relative to 1/12th mass of a carbon 12 atom

Question 8

relative atomic mass

Answer 8

average mass of an atom relative to 1/12th mass of a carbon 12 atom

Question 9

isotope

Answer 9

atoms of the same element with the same number of protons but a different number of neutrons

Question 10

(3)

1st ionisation energy

Answer 10

• the enthalpy change when one mole of electrons is removed
• from 1 mole of gaseous atoms to
• form 1 mole of gaseous 1+ ions

Question 11

(5)

steps of mass spectrometry

Answer 11

• ionisation - sample is vapourised and injected to the mass spectrometer (where there’s high voltage) and leaves +1 ions
• acceleration - +ve charged ions are accelerated towards a -ve charged detection plate
• ion drift - ions are deflected by a magnetic field into a curved path
• detection - when they hit the detection plate, they gain 1 e and produce a flow of charge
• analysis -combine w flight times to produce a spectra

Question 12

shape of an s-orbital

Answer 12

spherical ⭕

Question 13

shape of a p-orbital

Answer 13

dumbell (ish) or infinity ♾️

Question 14

shape of a d-orbital

Answer 14

clover(ish) 🍀

Question 15

(2)

periodicity

Answer 15

• a repeating trend/pattern
• across a period