How to play Flame Test Lab
Flame Test Lab is a free GCSE chemistry game about flame test colours. Each question shows a coloured flame. You pick the metal ion that gives that colour from four options, such as the sodium ion (Na⁺) or the copper(II) ion (Cu²⁺).
Before you start, choose whose colour words to use: AQA or Edexcel. The two boards describe two of the five flames in different words, and the game marks you against the board you pick. The words for the round appear above each flame.
From question 8, a faint second colour surrounds the flame. It comes from a second metal ion in the same sample. Name the ion that gives the main colour. The harder start brings these two-ion flames in from question 4.
You have 15 seconds for each flame. Pick the right ion in time and you score 15 points. Run out of time and the question counts as wrong. In practice mode there is no clock, and a right answer scores 10. After a miss, the game shows the right ion and its colour word.
The science behind flame test colours
A metal ion is a metal atom that has lost one or more electrons, so it has a positive charge. Chemists also call a positive ion a cation. Some metal ions give a flame a clear colour when you heat one of their compounds in it. That makes a flame test a quick way to find out which metal ion a solid contains.
At GCSE you need five ions. This table shows the colour word each board uses.
| Metal ion | AQA colour | Edexcel colour |
|---|---|---|
| Lithium, Li⁺ | crimson | red |
| Sodium, Na⁺ | yellow | yellow |
| Potassium, K⁺ | lilac | lilac |
| Calcium, Ca²⁺ | orange-red | orange-red |
| Copper(II), Cu²⁺ | green | blue-green |
AQA lists these colours in 4.8.3.1 of its GCSE Chemistry specification, 8462. Edexcel lists them in point 9.2C of 1CH0. The boards agree on sodium, potassium and calcium. For lithium, AQA says crimson, a deep red, and Edexcel says red. For copper, AQA says green and Edexcel says blue-green. Both words describe the same kind of flame, so learn the word your own board uses.
OCR's two chemistry specifications, J248 and J258, name the same ions for flame tests but do not print a colour word for any of them. That is why this game offers AQA and Edexcel wording only.
A sample can hold more than one metal ion. AQA points out that in a mixture, some flame colours can be masked, which means hidden by another colour. The two-ion questions in the game show this idea with a faint outer colour around a strong one.
Flame tests are part of the separate chemistry GCSE only. They are not in AQA Combined Science (8464) or Edexcel Combined Science (1SC0).
Tips for remembering flame test colours
- Lithium and calcium are the easiest pair to confuse, because both flames are red. Lithium is the deeper red. Calcium leans towards orange.
- Copper is the only ion of the five with a green flame, whichever board you take.
- Potassium's lilac is pale purple. It is the only flame of the five in that colour family.
- Sodium gives the one clear yellow flame in the set.
- In the two-ion questions, ignore the faint outer glow and name the colour at the centre. The faint colour belongs to the other ion, and that ion is often one of the options.
- Read the charge in the option too. Calcium and copper form 2+ ions, while lithium, sodium and potassium form 1+ ions.
The flames in the game are drawings, so no screen shade will match a real flame exactly. After each miss the game gives the colour word, and that word is what an exam answer needs.
Use Flame Test Lab in the classroom
Flame Test Lab suits Years 9 to 11 on the separate chemistry course, in lessons on identifying ions. Combined Science groups do not need flame tests for the exam. A round takes about five minutes.
Set the colour words to your board before the class starts. The game works well just after students do flame tests at the bench: they can compare what they saw with the words the exam expects. It also makes a good retrieval starter before a lesson on the other ion tests. For a follow-up, ask students to write the five ions and colours from memory, then play a round with the other board's words and spot which answers change.
Practice mode takes the clock away for students who need thinking time. The page for teachers explains how to set up the games for a class, with no accounts to create.
Similar games
Lithium, sodium and potassium all sit in Group 1, which you can place in Periodic Table Challenge. For more on how metals behave, rank them in Reactivity Rank. You can also name the salts that acids make in pH Detective or balance neutralisation equations in Balance It. Every game is on the all games page.
Flame test questions
Here are short answers to questions that come up about flame tests.
What are the flame test colours for GCSE chemistry?
Lithium gives a crimson or red flame, sodium yellow, potassium lilac, calcium orange-red, and copper green or blue-green. Where two words are given, the first is AQA's and the second is Edexcel's.
Do AQA and Edexcel use the same flame test colours?
They agree on sodium, potassium and calcium. For lithium, AQA says crimson and Edexcel says red. For copper, AQA says green and Edexcel says blue-green. Use the word your own board prints.
Are flame tests in GCSE Combined Science?
No. AQA and Edexcel only include flame tests in their separate chemistry GCSEs, 8462 and 1CH0. OCR also keeps them for the separate chemistry course.
Why can a flame test give an unclear result?
If the sample holds a mixture of metal ions, one flame colour can hide another. AQA calls this masking. A flame test is easiest to read when the sample contains one metal ion.