Elements with one valence electron are known as Group 1 elements or alkali metals. These elements belong to the first column of the periodic table and include:

1. Hydrogen (H)

2. Lithium (Li)

3. Sodium (Na)

4. Potassium (K)

5. Rubidium (Rb)

6. Cesium (Cs)

7. Francium (Fr)

Each of these elements has an outermost shell with a single valence electron, which is loosely bound to the nucleus. This makes them highly reactive and eager to donate their valence electron, forming positive ions (cations).