Question

Explain giving justification the trends in the following properties of elements on moving from left to right in a period,in the modern periodic table.
(a) Variation of valency.
(b)Change of atomic mass.
(c)Metallic to non metallic character

Answer 1

valance same for all elements from top to bottom in groups and from left to right increases from 1 to 4 and decreases to 0