Question

How many ,
element are present in 4a
5th
period?

Answer 1

Answer:

The fifth period starts with atomic no. 37 and ends with atomic no.54. The last electrons enters in 58, 4d or 5p orbits. So total no. of elements on fifth period is (2+10+6) = 18 elements.

Answer 2

Explanation:

The elements of group 15 (column) VA of the periodic table all have electron configurations of

s

2

p

3

, giving them five valence electrons. These elements include Nitrogen (N), Phosphorus (P), Arsenic (As), Antimony (Sb) and Bismuth (Bi).

Looking at the fourth energy level or period (row) of the periodic table we will find that the element Arsenic is in the 4th energy level and in group 17. Arsenic has an electron configuration of

[

A

r

]

4

s

2

3

d

10

4

p

3

. The s and p orbitals of arsenic have 2 and 3 electrons respectively making 5 valence electrons.

I hope this was helpful.