4d, 5p, 5f and 6p orbitals are arranged in the order of decreasing energy. The correct option is :

Options

A. `5f gt 6p gt 5p gt 4d `
B. `6p gt 5f gt 5p gt 4d`
C. `6p gt 5f gt 4d gt 5p`
D. `5f gt 6p gt 4d gt 5p`

Answer

A

Explanation

`(n+1)` value for, `4d=overset(n)4+overset(l)2=6`
`5p=5+1=6`
`5f=5+3=8`
`6p=6+1=7`
Lower value of `(n+l)` signifies lower energy
In case of 4d and 5p, lower value of n in 4d has compare to 5p. So, 4d has less energy in comparison to 5p.
`:.` Correct order of energy will be `5f gt 6p gt 5p gt 4d`