AQA · Week 1 of the 13-week plan
Eight new exam-style questions with full worked solutions, and online recall cards for your review days. None of these questions are in the book, so they are a fresh test of the same ideas.
What this chapter covers
- 1.1 Atoms, sub-atomic particles and isotopes
- 1.2 Relative masses
- 1.3 Time-of-flight (TOF) mass spectrometry
- 1.4 Reading a mass spectrum
- 1.5 Shells, sub-shells and orbitals
- 1.6 Electron configurations and blocks
- 1.7 Ionisation energies
- 1.8 Evidence for shells and sub-shells
Extra worked questions
Cover the solution, answer on paper, then mark yourself against each step. Each step shows the mark it earns.
All 8 worked solutions are free for members. The first one is open to everyone.
Particles in ions
State the numbers of protons, neutrons and electrons in (a) the ion 56Fe3+ and (b) the ion 32S2−.
Try it first, then show the worked solution
| (a) Protons and neutrons | Fe has atomic number 26, so 26 protons. Neutrons = 56 − 26 = 30. | 1 |
|---|---|---|
| (a) Electrons | A 3+ ion has lost three electrons: 26 − 3 = 23 electrons. | 1 |
| (b) All three | S has atomic number 16: 16 protons, 32 − 16 = 16 neutrons, and 16 + 2 = 18 electrons. | 1 |
Answer: (a) 26 p, 30 n, 23 e (b) 16 p, 16 n, 18 e
Examiner tip: Only the electrons change when an atom becomes an ion. A positive charge means electrons lost; a negative charge means electrons gained.
Relative atomic mass of silicon
A sample of silicon contains 92.23% 28Si, 4.67% 29Si and 3.10% 30Si. Calculate the relative atomic mass of silicon in this sample, to one decimal place.
Join free to see the full worked solution. Join free or log in.
Isotope abundances of antimony
A sample of antimony contains only 121Sb and 123Sb. Its relative atomic mass is 121.8. Calculate the percentage abundance of each isotope.
Join free to see the full worked solution. Join free or log in.
Configurations of iron and copper
Give the full electronic configuration, in s, p, d notation, of (a) an iron atom, (b) an Fe2+ ion and (c) a copper atom.
Join free to see the full worked solution. Join free or log in.
Which group? Successive ionisation energies
The first six ionisation energies of a Period 3 element Z, in kJ mol−1, are 1012, 1907, 2914, 4964, 6274 and 21 267. Deduce the group of Z, explain your answer and identify Z.
Join free to see the full worked solution. Join free or log in.
Comparing sodium and potassium
The first ionisation energy of sodium is 496 kJ mol−1 and of potassium is 419 kJ mol−1. The second ionisation energy of sodium is 4562 kJ mol−1. (a) Explain why the first ionisation energy of potassium is lower than that of sodium. (b) Explain why the second ionisation energy of sodium is so much larger than the first.
Join free to see the full worked solution. Join free or log in.
Identify an ion from its time of flight
In a time-of-flight mass spectrometer, every ion is accelerated to a kinetic energy of 3.00 × 10−16 J. A singly charged ion of a Period 3 noble gas takes 1.05 × 10−5 s to travel along a flight tube 1.00 m long. Calculate the mass of the ion and identify the isotope. Use KE = ½mv2 and the Avogadro constant, 6.02 × 1023 mol−1.
Join free to see the full worked solution. Join free or log in.
The mass spectrum of chlorine gas
Chlorine has two isotopes, 35Cl (75%) and 37Cl (25%). In the mass spectrum of chlorine gas, Cl2, there are three peaks for Cl2+ ions. (a) Give the m/z value of each of these three peaks and the isotopes that make up each ion. (b) Calculate the ratio of the heights of the three peaks.
Join free to see the full worked solution. Join free or log in.
Recall cards
Answer out loud or on paper before you turn the card. Only a complete answer counts as "Got it".
These are 3 of 18 recall cards. Premium members get the full deck for every chapter, ready for each review day in their plan.
Your review days
Count from your Day 0, the day you finish learning this chapter. Your plan schedules these for you.
- +1 Recall cards (these online cards, or the cards in the book)
- +3 Recall cards and Q1 to Q4
- +7 Recall cards and Q5 to Q8
- +14 Recall cards and Q9 to Q12
- +30 Full chapter test, timed
All questions on this page are original and are not in the book. This site is independent and is not endorsed by AQA or Pearson Edexcel.