When a nucleus decays it does not vanish, it transforms, and the bookkeeping is exact. Count the nucleons and the protons before and after, and they always balance.
In alpha decay the nucleon number falls by 4 and the proton number by 2. In beta decay the nucleon number stays the same and the proton number rises by 1. A decay equation must balance the nucleon numbers and the proton numbers on both sides.
In alpha decay the nucleus loses 2 protons and 2 neutrons; in beta decay a neutron changes into a proton, emitting an electron.
A decay equation must balance both the nucleon numbers and the proton numbers.
Trigger alpha and beta decays and see how the nucleon and proton numbers shift.
Four quick checks. Each correct answer earns XP and lights this skill on your star map.
In alpha decay, the nucleon number...
In alpha decay, the proton number...
In beta decay, the nucleon number...
In beta decay, the proton number...
Alpha drops both numbers; beta keeps the nucleon number but raises the proton number.
A nucleus with nucleon number 226 and proton number 88 emits an alpha particle. Find the daughter nucleus numbers.
In alpha decay both numbers fall, the nucleon number by 4 and the proton number by 2. In beta decay the nucleon number does not change; only the proton number rises by 1 as a neutron becomes a proton. Always balance both numbers.
Unlocks once the four checks above are done. Worth more XP, written in the style of Paper 2.
A nucleus of nucleon number 226 and proton number 88 emits an alpha particle. The daughter nucleus has...
When a nucleus emits a beta particle, its proton number and nucleon number change as follows...
Carbon-14 (proton number 6) decays by beta emission. The daughter nucleus has a proton number of...
Decay equations are mapped. Keep the chain going.