Question

Name the period and group to which the element with No.15 belongs​

Answer 1

Explanation:

The element with atomic number 15 belonging to group 15 is present in third period (Period-3). It has therefore, three shells. The element is Phosphorus (P), Configuration = 2, 8, 5, Valency = 5 or 3 (8-5=3) Nature = Non-metal.

Answer 2

Atomic number of Element = 15

Configuration ---->

1s² 2s² 2p⁶ 3s² 3p³

⠀⠀⠀⠀⠀(Valence shell)

Calculation of Period---

Number of outermost orbit = 3

So, Period number = 3

Calculation for Group number---

Here we can see that last electron in filling in p block. So it is the p-block element.

Number of electrons is valence shell = 2 + 3 = 5

Number of group for the element

= 10 + valence electron

= 10 + 5

= 15