a.  Valency
    b.  Symbol
    c.  Monoatomic molecule
    d.  Diatomic molecule

Asked by Topperlearning User | 15th Jul, 2015, 09:19: AM

Expert Answer:

  1. Valency: Valency is the number of hydrogen atoms which can combine with one atom of the element forming a compound.
  2. Symbol: A symbol is a short form or abbreviated name of the element.
  3. Monoatomic molecule: A molecule is monoatomic when it contains only one atom.
  4. Diatomic molecule: A molecule is diatomic when it contains two atoms.

Answered by  | 15th Jul, 2015, 11:19: AM