* Atomic number: The atomic number defines an element. It represents the number of protons in an atom's nucleus. Radioactive decay does not change the number of protons in the nucleus. Instead, it changes the number of neutrons, which affects the element's identity but not its atomic number.
* Mass number: The mass number is the sum of protons and neutrons in the nucleus. While radioactive decay changes the number of neutrons, it usually does so in a way that maintains the overall mass number.
Here's how radioactive decay works in relation to these concepts:
* Alpha decay: An alpha particle, which is essentially a helium nucleus (2 protons and 2 neutrons), is emitted from the nucleus. This reduces the atomic number by 2 and the mass number by 4. For example, uranium-238 decays into thorium-234.
* Beta decay: A neutron within the nucleus decays into a proton, an electron, and an antineutrino. The electron is emitted from the atom (as a beta particle). This increases the atomic number by 1 but leaves the mass number unchanged. For example, carbon-14 decays into nitrogen-14.
* Gamma decay: This decay process involves the emission of gamma rays, which are high-energy photons. This does not change the atomic number or mass number of the nucleus. It simply releases excess energy from the nucleus.
Therefore, while radioactive decay does change the identity of an element by altering the number of neutrons, it does not alter the fundamental properties that define an element – its atomic number and mass number.
