It is also very small compared to the overall size of the atom. A rough analogy of the scale of the nucleus to the atom is the relative size of a pea in a football stadium. Since each electron is about 5000 times lighter than either a proton or a neutron, almost all of the mass of the atom is at its center. These electrons fill the space around the nucleus. As we will see, changes in the arrangement of electrons around atoms makes it possible for atoms to bond together.
Atoms have the same nimber of electrons as they have protons.
For stable nuclei, those that aren't radioactive, the number of protons and neutrons will be nearly equal. Molecules, Compounds, and Ions A molecule type of particle that results from chemical bonding between two or more atoms. We will explore different types of bonds later on, but at this early stage in the course, you should be aware that a molecule is the smallest piece of a substance that retains the properties of the substance. These substances can be elements or compounds, which are substances made up of two or more elements in a constant ratio. In addition to making compounds by bonding together, atoms can also lose or gain one or more electrons to form charged particles called ions.