Beta decay is a type of radioactive decay in which an unstable atomic nucleus transforms into a more stable one. This process involves the conversion of a neutron into a proton and an electron, which is ejected from the nucleus. The key point to understand is that this transformation directly impacts the atomic number of the element.
In more detail, the atomic number of an element is defined by the number of protons in its nucleus. When a neutron decays into a proton during beta decay, the total number of protons increases by one. As a result, the atomic number rises by one. For instance, if we take the beta decay of carbon-14, which has 6 protons, it decays into nitrogen-14, which contains 7 protons. This change in atomic number leads to the formation of a different element.
To summarize, beta decay increases the atomic number because it involves the conversion of a neutron into a proton, thereby increasing the number of protons in the nucleus. This process is essential in understanding how elements transform and change properties during radioactive decay.