Question

Give some examples of Dobereiner's triads. Explain how they are grouped as triads.

Answer 1

• Dobereiner's Law of Triads
  When elements are arranged in the order of increasing atomic masses, groups of three elements (known as triads), having similar chemical properties are obtained. The atomic mass of the middle element of the triad is equal to the arithmetic mean of the atomic masses of the other two elements.
• The triads are - (i) Lithium, Sodium, and Potassium

(ii) Chlorine, Bromine, and Iodine

(iii) Calcium, Strontium, and Barium

• They have similar chemical properties and form a triad.