questions

Question 1

Explain why the first ionisation energy of sulfur is lower than that of phosphorus

Answer 1

• electron being removed from and orbital containing two electrons
• repulsion between electrons

Question 2

Explain why the first ionisation energy of sodium is greater than that of potassium

Answer 2

the outer electron in a sodium atom is closer to the nucleus and less shielding from inner electron shells. these outweigh the greater nuclear charge

Question 3

Explain why the difference between the second and third ionisation energies of calcium
is much larger than the difference between the first and second ionisation energies

Answer 3

• the 3rd electron is lost from a shell
• the first two electrons experience similar shielding

Question 4

Give a reason why the successive ionisation energies increase

Answer 4

electron removed is close to the nucleus

Question 5

State how the relative abundance of the two isotopes can be found

Answer 5

number of particles of each isotope detected in a mass spectrometer

Question 6

Explain the three ion pathways, A, B and C, shown in the region indicated by the arrow
X - mass spectrometer

Answer 6

A - ions with greater m/z are deflected less
B - ions are deflected by the magnetic field
C - ions with lower m/z are deflected more

Question 7

Give the meaning of the term ‘periodicity’.
Illustrate your answer by referring to the atomic radii of the Period 2 and Period 3 elements.
Specific values of atomic radii are not required.

Answer 7

a trend of repeating properties
- atom radii decrease from left to right
- atomic radius trend is repeated in period 3