Electronic Configuration — Prelims Questions

Which of the following electronic configurations is incorrect according to the Aufbau principle, Pauli's exclusion principle, and Hund's rule?

What is the correct electronic configuration for the $Cr^{3+}$ ion (Atomic number of Cr = 24)?

How many unpaired electrons are present in a $Fe^{2+}$ ion (Atomic number of Fe = 26)?

Which of the following sets of quantum numbers is NOT allowed for an electron in an atom?

Which of the following elements has an electronic configuration with 5 electrons in its $3d$ subshell?

An atom has a total of 17 electrons. What is its electronic configuration?

Which of the following statements about electronic configuration is INCORRECT?