I would assume potassium-42 decays into calcium-42 via beta decay.
Potassium-42 --> Calcium-42 + electron
The product of beta decay of bismuth-209 is thallium-209. During beta decay, a neutron in the bismuth nucleus is converted into a proton, resulting in the emission of a beta particle (electron) and an antineutrino.
The product of the beta decay of bismuth-214 is the stable element polonium-214. During beta decay, a neutron in the nucleus of bismuth-214 is converted into a proton, with the emission of an electron (beta particle) and an antineutrino.
A gamma wave...
The decay product of uranium 238 by alpha disintegration (not beta or gamma) is thorium 234.
There are two types of beta decay, and they are beta plus (beta +) decay and beta minus (beta -) decay. A post already exists on beta decay, and a link to that related question can be found below.
The product of beta decay of bismuth-209 is thallium-209. During beta decay, a neutron in the bismuth nucleus is converted into a proton, resulting in the emission of a beta particle (electron) and an antineutrino.
The daughter product in the beta decay of 144Ce is 144Pr, which stands for promethium. Promethium is a radioactive element that forms as a result of the beta decay of cerium-144.
The product of the beta decay of bismuth-214 is the stable element polonium-214. During beta decay, a neutron in the nucleus of bismuth-214 is converted into a proton, with the emission of an electron (beta particle) and an antineutrino.
A gamma wave...
Bismuth-214 produces Polonium-214 by beta- decay. It also produces Thallium-210 by alpha decay, though at a much smaller percentage.
The other product in the beta decay of zirconium-93 is niobium-93. In beta decay, a neutron in the nucleus is converted to a proton, resulting in the formation of a new element with one higher atomic number.
The product of nitrogen-17 beta decay is oxygen-17. During beta decay, a neutron in the nitrogen-17 nucleus is converted into a proton, resulting in the emission of a beta particle (an electron) and an electron antineutrino.
A beta particle
We know that iodine-131 will undergo beta minus decay, and an electron will appear as a result. (An electron antineutrino will also be produced, but we don't want to go there in this topic.)
The decay product of potassium in a process called beta decay is calcium. Potassium-40 undergoes beta decay to become argon-40, which then decays further to become calcium-40 over a long period of time.
There is a difference between beta emitters and beta particles. In situations where an atomic nucleus exhibits nuclear instability due to too many neutrons for the number of protons or vice versa, that nucleus may undergo beta decay. It the decay event occurs, that atom is considered a beta emitter. The emitted particle is the beta particle. That's the difference. (There are two different beta particles, so check the articles on beta decay to get the scoop.)
The decay product of uranium 238 by alpha disintegration (not beta or gamma) is thorium 234.