Question

In which of the following set of orbits, electrons have equal orbital angular momentum?

• A. $1s$ and $2s$
• B. $3d$ and $4d$
• C. $2p$ and $5p$
• D. All of the above

Answer 1

The correct option is A $1s$ and $2s$

Orbital angular momentum L of an electron in a subshell with azimuthal quantum number $l$ is given by

$L=\frac{h}{4\pi }\sqrt{l(l+1)}$

For $s$ subshell there is only one value of $l$ i.e $0$.

Therefore, for $1s$ and $2s$.