Potassium-40 undergoes three different modes of radioactive decay (Beta decay, Positron decay, and Electron Capture decay). Write balanced nuclear reactions for each of these decay modes. Are the products stable (not radioactive)?
On this forum it isn't easy to write isotopes so I use the first number to show atomic number (protons) and second number to show mass number (protons + neutrons). I'll do the first one for beta decay.
19K40 ==> -1eo + 20Ca40
Note the first number add up on both sides and the second number adds up on both sides.
To write the balanced nuclear reactions for each decay mode of Potassium-40 (K-40), we need to understand the decay processes and the resulting products.
1. Beta decay: In beta decay, a neutron in the nucleus is converted into a proton, releasing a beta particle (electron) and an electron antineutrino. The general form for beta decay can be represented as:
K-40 --> Ca-40 + e- + ve
2. Positron decay: In positron decay, a proton in the nucleus is converted into a neutron, releasing a positron (antielectron) and an electron neutrino. The general form for positron decay can be represented as:
K-40 --> Ar-40 + e+ + ve
3. Electron capture decay: In electron capture decay, an electron from the closest electron shell is captured by the nucleus, combining with a proton to form a neutron. This process also results in the release of an electron neutrino. The general form for electron capture decay can be represented as:
K-40 + e- --> Ar-40 + ve
Now, regarding the stability of the products, both Calcium-40 (Ca-40) and Argon-40 (Ar-40) are considered stable isotopes. They do not undergo radioactive decay further, meaning they are not radioactive themselves. Therefore, the products of the decay of Potassium-40 in these three modes are stable (not radioactive).