Question 1:

Which of the following represents the correct electron configuration for an oxygen atom?

Explanation: The correct answer is A) 1s² 2s² 2p⁴. An oxygen atom has 8 electrons, and its electron configuration follows the order of filling the 1s, 2s, and 2p orbitals with a maximum of 2 electrons per orbital.

Question 2:

How many unpaired electrons are present in a nitrogen atom?

Explanation: The correct answer is B) 1. A nitrogen atom has 7 electrons, and its electron configuration is 1s² 2s² 2p³. The 2p sublevel has three orbitals, and one of them will have an unpaired electron.

Question 3:

Which of the following represents the correct orbital notation for a sulfur atom?

Explanation: The correct answer is B) 1s² 2s² 2p⁶ 3s² 3p⁴. A sulfur atom has 16 electrons, and its electron configuration follows the order of filling the 1s, 2s, 2p, 3s, and 3p orbitals.

Question 4:

Which of the following orbitals has the highest energy?

Explanation: The correct answer is C) 2p. In a given shell, the s sublevel has the lowest energy, followed by the p sublevel, and then the d sublevel. Therefore, within the second shell, the 2p orbital has the highest energy.

Question 5:

What is the maximum number of electrons that can occupy the 4d sublevel?

Explanation: The correct answer is C) 10. The 4d sublevel can hold a maximum of 10 electrons, with each orbital within the sublevel accommodating 2 electrons.