Question

Which is the correct order of increasing energy of the listed orbitals in the atom of titanium?
(At. no. $Z=22$)

• A. $3s$ $3p$ $3d$ $4s$
• B. $3s$ $3p$ $4s$ $3d$
• C. $3s$ $4s$ $3p$ $3d$
• D. $4s$ $3s$ $3p$ $3d$

Answer 1

The correct option is B $3s$ $3p$ $4s$ $3d$

The correct order of increasing energy of the listed orbitals in the atom of titanium is $3s<3p<4s<3d$.
The energy of 4s orbital is lower than the energy of 3d orbital.
Due to this, 4s orbital is filled first followed by 3d orbital.