Question

the valency of an element y present in the 2nd period of the modern periodic table is 4. what is the atomic number of the element present just below y in the periodic table​

Answer 1

Answer:

carbon atomic number 6

Answer 2

Explanation:

There are 7 periods in the modern periodic table.

Metallic character tends to decrease on going across a period whereas the number of valence electrons increases in a period and valency first increases from 1 to 4 and then decreases from 4 to 0.

Atomic radius increases from top to bottom within a group. This is caused by the addition of a new shell. In a group, the number of valence electrons does not change. Hence, all the elements of one group have the same valency.