🎮 How Many Neutrons?

📖 About this game

A game on the lesson of the nucleus, whose text reads: the atomic number is the number of protons in the nucleus of an atom, and the mass number is the sum of the protons and the neutrons in it. So the number of neutrons is found by subtracting the atomic number from the mass number, and never by adding them. Why two numbers are given and the third asked for: the subtraction is the lesson, and a learner who memorised the two definitions without subtracting has not used them. The distractors are all computed from the same two numbers and each answers to a mistake: the atomic number itself for a learner who thought neutrons were protons, the sum for one who added instead of subtracting, and the mass number for one who thought the nucleus was all neutrons. The isotopes shown always have a neutron count different from the atomic number, because if the two were equal the first mistake would land on the right answer and pass unseen. The nucleus is built at the reveal from those same two numbers, ball by ball, so the learner counts it with his own eyes. Ten nuclei. No sign-up.

🕹️ How to play

1. Read the mass number and the atomic number of the atom.
2. Subtract the atomic number from the mass number.
3. Tap the result you reached.
4. Every nucleus you get first try counts for you.