The mass changes with the ejection of a neutron. The ejection of a proton changes the element. The atom becomes neutral because it loses a proton and electron. An ion forms when the electron is ejected.

Let's break down the information provided regarding atomic changes and their implications step by step. 1. **Ejection of a Neutron:** - When a neutron is ejected from an atom, the mass of the atom decreases because neutrons contribute to the atomic mass. However, the atomic number (which defines the element) remains unchanged since neutrons do not affect the number of protons in the nucleus. 2. **Ejection of a Proton:** - The ejection of a proton results in a change of the atomic number, which means the atom transforms into a different element. For example, if a carbon atom (atomic number 6) loses a proton, it becomes a boron atom (atomic number 5). 3. **Atom Becomes Neutral:** - An atom is neutral when it has an equal number of protons (positively charged) and electrons (negatively charged). If an atom loses a proton, it also loses an electron to maintain neutrality. This means that the overall charge of the atom remains zero. 4. **Formation of an Ion:** - When an electron is ejected from an atom, the atom becomes positively charged because it has more protons than electrons. This positively charged atom is known as a cation (a type of ion). Conversely, if an atom gains an electron, it becomes negatively charged and is referred to as an anion. ### Summary: - Ejecting a neutron changes the mass but not the element. - Ejecting a proton changes the element. - Losing a proton and an electron keeps the atom neutral. - Ejecting an electron forms a positively charged ion (cation). If you have any specific questions or need further clarification on any of these points, feel free to ask!