| # | Concept | Culture | Statement | Freq. |
|---|---|---|---|---|
| 1 | protium | chemistry | Protium is the most common isotope of hydrogen, with one proton and no neutrons. | 1 |
| 2 | protium | chemistry | In chemistry and physics, protium is studied as the simplest and most abundant hydrogen isotope. | 1 |
| 3 | protium | chemistry | Protium is the most common isotope of hydrogen, with a single proton and no neutrons. | 1 |
| 4 | stoichiometry | Chemical science community | Stoichiometry calculations are common in chemical laboratories and industries. | 1 |
| 5 | strontium hydroxide | chemistry community | A strong base commonly used in chemical reactions and laboratory experiments. | 1 |