Question

a) if all the orbitals shown in the 3d model are completely filled, how many electrons does this element have? justify your answer.
b) write the correct sequence of subshells represented in the diagram, in order from lowest to highest energy level.

Explanation:

Step1: Identify the orbitals

The diagram shows \(s\) and \(d\) orbitals. An \(s\) sub - shell has \(1\) orbital and a \(d\) sub - shell has \(5\) orbitals.

Step2: Calculate the number of electrons

Each orbital can hold a maximum of \(2\) electrons.
For the \(s\) orbital: \(1\times2 = 2\) electrons.
For the \(d\) orbitals: \(5\times2=10\) electrons.
Total electrons \(=2 + 10=12\) electrons.

Step3: Determine the sub - shell energy order

According to the Aufbau principle, the \(s\) sub - shell has lower energy than the \(d\) sub - shell.

Answer:

a) The element has \(12\) electrons. Justification: There is \(1\) \(s\) orbital (\(2\) electrons) and \(5\) \(d\) orbitals (\(10\) electrons), so \(2 + 10=12\) electrons.
b) The sequence of sub - shells from lowest to highest energy level is \(s\), \(d\).