Which of the following sub-levels is correctly designated?

• 1p⁵

• 3f⁹

• 2p⁶

• 3d¹¹

Answer explanation

The correct designation is 2p⁶ because the p sub-level can hold a maximum of 6 electrons. The other options exceed the maximum electron capacity for their respective sub-levels.

According to Pauli Exclusion Principle, how many electrons may occupy a single orbital?

• 1

• 2

• 4

• 8

Answer explanation

According to the Pauli Exclusion Principle, a single orbital can hold a maximum of 2 electrons, provided they have opposite spins. Therefore, the correct answer is 2.

“An electron should occupy the lowest energy level first before the higher energy level” is stated in what rule?

• Hund's rule

• Pauli Exclusion Principle

• Aufbau Principle

• All of the above.

Answer explanation

The statement refers to the Aufbau Principle, which states that electrons fill the lowest energy levels first before occupying higher ones. Hund's rule and the Pauli Exclusion Principle address different aspects of electron configuration.

What rule states that single electrons must occupy each equal-energy orbital before additional electrons can occupy the same orbitals.

• Hund's rule

• Pauli Exclusion Principle

• Aufbau Principle

• None of the choices.

Answer explanation

Hund's rule states that single electrons must occupy each equal-energy orbital before pairing up. This minimizes electron-electron repulsion and is crucial for understanding electron configurations in atoms.

What is the electron configuration of Argon?

• 1s² 2s² 2p⁶

• 1s² 2s² 2p⁶ 3s¹

• 1s² 2s² 2p⁶ 3s²

• 1s² 2s² 2p⁶ 3s² 3p⁶

Answer explanation

Argon has 18 electrons. The correct electron configuration is 1s² 2s² 2p⁶ 3s² 3p⁶, filling the 3s and 3p orbitals completely, which corresponds to its position in the periodic table as a noble gas.

What model of the atom replaced Bohr's model?

• Heisenberg's model

• Thomson's model

• Rutherford's model

• Quantum Mechanical model

Answer explanation

The Quantum Mechanical model replaced Bohr's model by introducing the concept of probability distributions for electron positions, rather than fixed orbits, providing a more accurate representation of atomic behavior.

How many energy levels are currently present on the periodic table?

• 18

• 7

• 6

• 4

Answer explanation

The periodic table has 7 energy levels, corresponding to the 7 rows (periods) of elements. Each period represents a principal energy level, confirming that the correct answer is 7.

How many orbitals are there in a p-sublevel?

• 1

• 3

• 5

• 7

Answer explanation

A p-sublevel contains 3 orbitals, designated as px, py, and pz. Each orbital can hold a maximum of 2 electrons, making the p-sublevel capable of accommodating a total of 6 electrons.

What atom matches this electron configuration?
1s²2s²2p⁶3s²3p⁶4s²3d¹⁰

• Zinc

• Copper

• Nickel

• Germanium

Answer explanation

The electron configuration 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ corresponds to the element Zinc, which has an atomic number of 30, indicating it has 30 electrons.

What atom matches this electron configuration?
1s²2s²2p⁶3s²3p⁶4s²3d¹⁰

• Zinc

• Copper

• Nickel

• Germanium

Answer explanation

The electron configuration 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ corresponds to Zinc, which has an atomic number of 30. This configuration shows a complete filling of the 3d subshell and the 4s subshell, characteristic of Zinc.