Question

write a notes on triads and periods​

Answer 1

Triad was an group of three

elements in which atomic mass of middle element is mean of atomic mass of other two elements this triad

was made by Doberainer.

Period is concept of periodic table. There is 7 periods in modern periodic table.

Answer 2

Triads is a classification of three elements grouped by Dobereiner.The horizontal row in a periodic table is called as a period.

PERIODIC TABLE:

• Different scientists have made contribution in classifying elements.
• Dobereiner grouped the elements into triads.
• The group consists of three elements,so the name triad.
• Mendeleev stated the periodic law and found the periodic table.
• The horizontal rows in a periodic table is called as period.