An electron is transferred from sodium to chlorine. Sodium becomes a positive ion and chlorine becomes a negative ion. The positive and negative ions attract each other and form the ionic compound ...

Tell students that ions are atoms or molecules that have either a positive or negative charge. 2. Show students a model of a salt crystal on the molecular level. Explain that one way to make a model ...

When solar wind strikes the Moon, it releases secondary particles, including positive, negative, and neutral ions. Detecting negative ions, which are short-lived and cannot reach orbit ...