Question 1: Electronic structure refers to the arrangement of electrons in an atom's orbitals. It determines the atom's chemical properties and reactivity.

Answer: It is the distribution of electrons in an atom's orbitals, which affects chemical behavior.

Question 1: Define the term 'electron configuration'.

Answer: Electron configuration is the distribution of electrons among the orbitals of an atom.

Question 2: Explain why electrons occupy specific energy levels in an atom.

Answer: Electrons occupy specific energy levels to minimize energy, following the Aufbau principle, Pauli exclusion principle, and Hund's rule.

Question 1: Calculate the total number of electrons in a neutral atom of sulfur (S).

Answer: 16

Question 2: Write the electron configuration of a calcium atom (Ca) using noble gas notation.

Answer: [Ar] 4s²

Question 3: How many electrons are in the third energy level (n=3) of a phosphorus atom (P)?

Answer: 5

Question 1: Describe a safe laboratory procedure to observe the flame test for identifying elements, focusing on safety precautions related to electronic structure analysis.

Answer: Ensure proper ventilation, wear safety goggles and gloves, avoid inhaling fumes, and handle chemicals with care. Use a clean wire loop to introduce samples into the flame, and observe the color change to identify elements.

Question 1: An unknown element shows a bright violet flame during testing. Based on electronic structure principles, which element could it be and why?

Answer: It could be potassium, because potassium's electrons excite to higher energy levels and emit violet light when returning to lower levels.

Question 1: Describe the Aufbau principle and its role in determining an atom's electronic structure. (6 marks)

Answer: The Aufbau principle states that electrons fill atomic orbitals starting from the lowest energy level to higher levels. This rule helps predict the electron configuration of atoms, ensuring electrons occupy orbitals in an order that minimizes energy. It explains the arrangement of electrons in noble gases, transition metals, and other elements.

Question 1: Explain how understanding electronic structures is essential in the development of semiconductor devices like computer chips.

Answer: Electronic structure determines how electrons move within materials, affecting conductivity. Understanding electron arrangements allows scientists to manipulate materials to create efficient semiconductors used in computer chips and electronic devices.