Question

how would you justify the presence of 18 element in the 5th period of the periodic table

Answer 1

Answer:

A 5.0 cm tall object is placed perpendicular to the principal axis of a convex lens of focal length 20

cm. The distance of the object from the lens is 30 cm. By calculation determine

(i) the position and (ii) the size of the image formed.

Answer 2

When ,

• n = 5
• l = 0 , 1 , 2 , 3

$\rightarrow$The order in which the energy of the available orbitals 4d , 5s and 5p increases is 5s < 4d < 5p.

$\rightarrow$The total number of orbitals available are 9.

$\rightarrow$ The maximum number of electrons that can be accommodated is 18 and therefore 18 elements are there in the 5$^{th}$ period.