Question 1: Define 'electronic structure' of an atom.

Answer: The arrangement of electrons around the nucleus of an atom in different energy levels or shells.

Question 2: Explain why electrons occupy specific energy levels or shells around the nucleus.

Answer: Electrons occupy specific energy levels to minimize energy and follow the principles of quantum mechanics, filling the lowest available energy levels first.

Question 3: What is the maximum number of electrons that can occupy the second energy level (shell)?

Answer: 8

Question 4: Describe the order in which electrons fill energy levels in an atom (e.g., 1s, 2s, 2p, etc.).

Answer: Electrons fill energy levels starting from the lowest energy level, following the Aufbau principle. The order is 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, and so on, with electrons filling orbitals within each level according to the Pauli exclusion principle and Hund's rule.

Question 5: Which sublevel contains a maximum of six electrons?

Answer: d

Question 6: Fill in the blank: The electron configuration of oxygen (O) is 1s² 2s² ____ 2p⁴.

Answer: 2p

Question 7: How does the electronic structure of an atom influence its chemical reactivity?

Answer: Electrons in the outermost energy level (valence electrons) determine how an atom interacts with others. Atoms tend to gain, lose, or share electrons to achieve a full outer shell, affecting their reactivity.

Question 8: Describe a simple experiment to observe the emission spectrum of a hydrogen atom and explain what information it provides about electronic structure.

Answer: By passing electrical energy through hydrogen gas in a spectroscope, the atom emits light at specific wavelengths. Analyzing these wavelengths reveals the energy differences between electron energy levels, confirming the quantized nature of electronic structure.

Question 9: Identify the element with the electronic configuration: 1s² 2s² 2p⁶ 3s² 3p⁴.

Answer: Sulfur

Question 10: Explain how the electronic structure of aluminum contributes to its use in aerospace industries.

Answer: Aluminum's electronic structure, with three electrons in its outer shell, makes it lightweight, malleable, and resistant to corrosion, ideal for aerospace applications.

Question 11: What is the significance of the Pauli exclusion principle in determining an atom's electronic structure?

Answer: It states that no two electrons in an atom can have the same set of quantum numbers, which explains the arrangement of electrons in different orbitals and sublevels.