Question

In the animation, you can see that the electrons occupy different orbitals according to the energy level of each orbital. A single box represents an orbital. The unpaired electron is represented aswhereas the paired electrons in the same orbital are represented by two arrows pointing in opposite directions:. Watch the animation and identify which of the following statements are correct.

Check all that apply.

	The He atom has two electrons that have parallel spin in its 1s orbital.
	In the Li atom, the 3s, 3p, and 3d orbitals have different energies.
	Electrons generally occupy the lowest energy orbital first.
	The arrangement of the orbitals is the same in a multielectron atom and a single-electron atom.
	The C atom has two unpaired electrons.
	The He atom has one electron each in 1s and 2s orbitals.

Answer 1

Concepts and reason

The concept used in this problem is filling of electrons in orbital. The arrangement of distributing the electrons in ground state among the orbitals, shells and subshells is called electronic configuration. The properties of an element are dependent on its electronic configuration.

Fundamentals

According to Pauli Exclusion Principle, in atom it’s not possible to have two electrons which have identical set of quantum numbers.

According to Aufbau Principle, the filling of electrons in ground state is done by the increasing order of energy of principal energy levels. When orbitals have same energy then the one having lower shell will be filled first. The order of increasing energies of orbitals is as follows:

${\rm{1s}} < {\rm{2s}} < {\rm{2p}} < {\rm{3s}} < {\rm{3p}} < {\rm{4s}} < {\rm{3d}}$

Also, half-filled electronic configurations and fully filled electronic configurations are more stable.

The He atom has two electrons that have parallel spin in its 1s orbital.

The arrangement of the orbitals is the same in a multielectron atom and a single-electron atom.

The He atom has one electron each in 1s and 2s orbitals.

All the above statements are incorrect.

In the Li atom, the 3s, 3p, and 3d orbitals have different energies.

Electrons generally occupy the lowest energy orbital first.

The C atom has two unpaired electrons.

Ans:

This statement is correct.

This statement is correct.

This statement is correct.