Question

When forming cations of transition metals, first remove electrons from the _________, then (if needed) from the _________.

A. innermost electron shell, outermost electron shell
B. outermost electron shell, innermost electron shell
C. 3d orbital, 4s orbital
D. 4s orbital, 3d orbital

Answer 1

For transition metals, cations are formed by first removing electrons from the 4s orbital and then, if necessary, from the 3d orbital.

Step-by-step explanation:

When forming cations of transition metals, electrons are removed starting from the 4s orbital, then (if needed) from the 3d orbital. This is because the 4s electrons are regarded as the outermost and highest energy electrons, despite being filled before the 3d electrons according to the Aufbau principle.

Therefore, the correct response to the student's question is: When forming cations of transition metals, first remove electrons from the 4s orbital, then (if needed) from the 3d orbital.