First 20 elements quiz: hydrogen to calcium
Practice the names, symbols and atomic numbers of the first 20 elements, from hydrogen (1) to calcium (20). These are the elements most chemistry courses ask you to know by heart, and they include the elements that make up water, table salt and almost all of your body.
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How it works
Each round has 10 questions drawn only from elements 1 to 20, mixing names, symbols and atomic numbers, with four options for each question. Every answer gets instant feedback, and your best score is saved in your browser.
Play it three ways: a classic round of 10 questions, a 60-second speed round (25 right answers earns a star), or survival, where you keep going until you miss three.
Tips
- Learn them in blocks of five: H, He, Li, Be, B; C, N, O, F, Ne; Na, Mg, Al, Si, P; S, Cl, Ar, K, Ca.
- Picture them on the table: hydrogen and helium in period 1, lithium to neon in period 2, sodium to argon in period 3, and potassium and calcium at the start of period 4.
- Use the columns: lithium (3), sodium (11) and potassium (19) are in group 1, eight places apart, and so are fluorine (9) and chlorine (17) in group 17.
- Watch the two Latin-based symbols in this range: Na for sodium and K for potassium.