AQA A LEVEL CHEMISTRY PAPER 3
7405 3 MARK SCHEME 2026 SCIENCE
SCRIPT SOLVED QUESTIONS
VERIFIED ANSWERS A+
◉ why is Buckminsterfullerene a good lubricant? (2 marks)
Answer: the molecules are spherical so will roll.
◉ Explain why diamond is hard? (2 marks)
Answer: giant structure so it has strong bonds
◉ explain the trend in boiling points of the halogens? (4 marks)
Answer: boiling point increases down the table because the size of
molecule increases. so the intermolecular forces increase in strength,
therefore more energy is needed to overcome the intermolecular forces
◉ explain why the reactivity of the halogens decreases going down the
group? (3 marks)
Answer: going down the group the outer shell electrons become further
from the nucleus, so the nucleus has less attraction for the outer electron.
so an electron is gained less easily.
◉ what does the mass number represent
Answer: how many protons and neutrons are in an atom
7405 3 MARK SCHEME 2026 SCIENCE
SCRIPT SOLVED QUESTIONS
VERIFIED ANSWERS A+
◉ why is Buckminsterfullerene a good lubricant? (2 marks)
Answer: the molecules are spherical so will roll.
◉ Explain why diamond is hard? (2 marks)
Answer: giant structure so it has strong bonds
◉ explain the trend in boiling points of the halogens? (4 marks)
Answer: boiling point increases down the table because the size of
molecule increases. so the intermolecular forces increase in strength,
therefore more energy is needed to overcome the intermolecular forces
◉ explain why the reactivity of the halogens decreases going down the
group? (3 marks)
Answer: going down the group the outer shell electrons become further
from the nucleus, so the nucleus has less attraction for the outer electron.
so an electron is gained less easily.
◉ what does the mass number represent
Answer: how many protons and neutrons are in an atom
