Chemistry AQA AS Unit 1 Atomic Structure Questions
State the two measurements that are recorded for each isotope in a mass spectrometer (2 marks)
M/Z ratio (1 mark) abundance (1 mark)
Write the full electron configuration of the Al2+ ion (1 mark)
1s2 2s2 2p6 3s1
A sample element R contains isotopes with mass numbers of 207, 207 and 208 in a 1:1:2 ratio of abundance. Calculate the relative atomic mass of the isotope to 1dp. (3 marks)
206+207+(2 x 208) (1 mark)/ 4 (1 mark) = 829/4 = 207.3(1 mark)
State why isotopes of an element have the same chemical properties (1 Mark)
Same number of electrons in outer shell
State the meaning of the term 'mass number' of an isotope (1 Mark)
Total number of protons and neutrons in the nucleus of an atom.
Define the term 'relative atomic mass' (2 Marks)
Average mass of an atom compared with 1/12th of carbon 12
How is a current generated in a mass spectrometer? (2 marks)
Electrons transferred at the detector (1 Mark) to the positive ion (1 Mark)
Give one reason why the second ionisation energy of silicon is lower then the second ionisation energy of aluminium. (1 Mark)
electron in silicon is more shielded OR electron removed from higher energy orbital.