Types of Radiation: Videos & Practice Problems

Nuclear reactions involve processes that occur within unstable atomic nuclei, fundamentally altering the number of protons in an atom. In a typical atom, electrons orbit a nucleus composed of protons, which carry a positive charge, and neutrons, which are neutral. The atomic number, defined by the number of protons, determines the identity of an element. Unlike conventional chemical reactions, where the identities of the reactants remain unchanged, nuclear reactions can transform one element into another entirely different element.

For instance, in a chemical reaction, we might see a balanced equation such as:

H_2 + N_2 \rightarrow NH_3

Here, the identities of hydrogen and nitrogen remain the same throughout the reaction. However, in nuclear reactions, the manipulation of protons can lead to the formation of new elements. For example, a nucleus of calcium-40 can undergo a transformation that results in the creation of argon. This illustrates that by changing the number of protons, we directly influence the identity of the element, highlighting the unique nature of nuclear chemistry.

Nuclear reactions, a fundamental aspect of nuclear chemistry, were significantly advanced by British physicist Ernest Rutherford, whose extensive research led to the naming of element 104 as Rutherfordium in his honor. These reactions can be categorized into three primary types: alpha decay (or alpha emission), beta decay (or beta emission), and gamma emission. Understanding these categories is crucial, as they describe how radioactive particles are involved in nuclear transformations.

The terms "decay" and "emit" indicate that the radioactive particle is a product of the reaction. For instance, in alpha decay, an alpha particle is emitted, while in beta decay, a beta particle is released. Gamma emission involves the release of a gamma particle. Conversely, the term "capture" refers to scenarios where these particles act as reactants, meaning they are absorbed rather than emitted. This distinction is vital, as it influences the resulting products of the reaction.

In alpha decay, the emission of an alpha particle alters the original element, while beta decay and gamma emission similarly transform the identity of the element involved. For example, a nuclear reaction might start with calcium and result in a completely different element, such as argon, due to the emission or capture of these particles.

As one delves deeper into nuclear reactions, additional processes such as positron emissions and electron capture will be explored, further expanding the understanding of how elements can change identity through these interactions. This highlights the profound differences between chemical and nuclear reactions, where the latter can lead to entirely new elements through the emission or capture of radioactive particles.