Elements with valency 1 are

Elements with valency 1 are either metals or non-metals (H is non-metal with valency 1)

Metals with Valency 1:

These are alkali metals (Group 1) that have one electron in their outermost shell. They tend to lose this electron to achieve a stable electronic configuration (forming +1 cations).

• Examples:
  • Hydrogen (H) (acts as a non-metal in most cases but can exhibit metallic behavior under certain conditions)
  • Lithium (Li)
  • Sodium (Na)
  • Potassium (K)
  • Rubidium (Rb)
  • Cesium (Cs)
  • Francium (Fr)

2. Non-Metals with Valency 1:

These are halogens (Group 17) that have seven electrons in their outermost shell. They tend to gain one electron to achieve a stable configuration (forming -1 anions).

• Examples:
  • Fluorine (F)
  • Chlorine (Cl)
  • Bromine (Br)
  • Iodine (I)
  • Astatine (At)
  • Tennessine (Ts)

Conclusion:

• Metals with valency 1 are typically electron donors (form positive ions).
• Non-metals with valency 1 are typically electron acceptors (form negative ion