Understanding Orbitals and Sublevels

What is the shape of an s orbital?

• Dumbbell

• Spherical

• Double dumbbell

• Cloverleaf

Answer explanation

The shape of an s orbital is spherical, meaning it is uniform in all directions around the nucleus. This distinguishes it from p orbitals, which have a dumbbell shape.

Which of the following is a type of p orbital?

• Spherical

• Dumbbell

• Cloverleaf

• Double dumbbell

Answer explanation

The correct answer is 'Dumbbell' because p orbitals have a characteristic dumbbell shape, which distinguishes them from s orbitals (spherical) and d orbitals (cloverleaf or double dumbbell shapes).

How many electrons can a single d sublevel hold?

• 2

• 6

• 10

• 14

Answer explanation

A single d sublevel can hold a maximum of 10 electrons. This is because there are five d orbitals, and each orbital can hold 2 electrons, resulting in 5 x 2 = 10 electrons.

According to the Pauli Exclusion Principle, how many electrons can occupy the same orbital?

• 1

• 2

• 3

• 4

Answer explanation

According to the Pauli Exclusion Principle, no two electrons can have the same set of quantum numbers in an atom. Therefore, a maximum of 2 electrons can occupy the same orbital, each with opposite spins.

What is the correct order of sublevel energy from lowest to highest?

Answer explanation

The correct order of sublevel energy from lowest to highest is 4s < 3d < 4p. The 4s sublevel is filled before the 3d sublevel, and the 4p sublevel has higher energy than both.

Which rule states that electrons fill orbitals starting with the lowest energy level first?

• Hund's Rule

• Pauli Exclusion Principle

• Aufbau Principle

• Heisenberg Uncertainty Principle

Answer explanation

The Aufbau Principle states that electrons occupy the lowest energy orbitals first before filling higher ones. This principle helps explain the electron configuration of atoms.

What is the maximum number of electrons that can be held in the p sublevel?

• 2

• 4

• 6

• 8

Answer explanation

The p sublevel can hold a maximum of 6 electrons. This is because it consists of three orbitals, each capable of holding 2 electrons, resulting in 3 x 2 = 6 electrons.

Which of the following is the correct electron configuration for oxygen (atomic number 8)?

Answer explanation

Oxygen has an atomic number of 8, meaning it has 8 electrons. The correct electron configuration is 1s² 2s² 2p⁴, which accounts for all 8 electrons in the appropriate energy levels.

What is the shape of a d orbital?

• Spherical

• Dumbbell

• Cloverleaf

• Linear

Answer explanation

The shape of a d orbital is cloverleaf, characterized by four lobes. This distinguishes it from s orbitals, which are spherical, and p orbitals, which are dumbbell-shaped.

• Chlorine

• Argon

• Sulphur

• Phosphorus

Answer explanation

The electron configuration [Ne] 3s^2 3p^5 corresponds to chlorine (Cl), which has 17 electrons. Chlorine is in period 3 and group 17 of the periodic table, confirming it as the correct answer.