Which of the following are correct ?
(1) Electron density in XY plane for `d_(x^(2)-y^(2))` orbital is zero.
(2) The energy of 3p-orbital is higher than the energy of 2p-orbital.
(3) `3p_(z)` orbital has one angular node.
(4) 4f-orbital has no radial node.

Options

A. 1, 2, 3, 4
B. 2, 3,1
C. 2, 3,4
D. 3, 4, 1

Answer

C

Explanation

1. In `d_(x^(2) - y^(2))` orbital, electrons are present on the x and y axis, hence electron density is not zero.
2. According to `(n + l)` rule, higher be the sum of `(n + l)`, higher is the energy.
`:.` For `3p, (n +l) = 3 + 1 = 4`
and for `2p, (n + l) = 2 + 1 = 3`
Thus, 3p has higher energy than 2p.
3. The quantum number l determines the number of angular nodes. (It is also known as nodal plane)
i.e., Number of angular nodes = value of l.
`:.` For `3p_(2)` adn l = 1
Thus, one angular node is present in `3p_(2)`-orbital.
4. 4f-orbital have n=4 and l = 3 and the number of radial nodes is `n-l -1 = 0 = 4- 3 - 1 = 0`.