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

Answer: The arrangement of electrons within an atom's energy levels or shells.

Question 2: Explain why electrons are arranged in shells around the nucleus of an atom.

Answer: Electrons occupy energy levels or shells to minimise energy and repel each other, resulting in a stable arrangement.

Question 3: What is the maximum number of electrons that can occupy the first two shells of an atom?

Answer: 2 electrons in the first shell and 8 in the second shell, totalling 10 electrons.

Question 1: Calculate the total number of electrons in a chlorine atom, given its atomic number is 17.

Answer: 17

Question 2: Write the electronic configuration of calcium (atomic number 20) using the notation 1s² 2s² 2p⁶ ...

Answer: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s²

Question 1: Describe a simple experiment to determine the electronic configuration of a metal ion using spectroscopic methods.

Answer: A common method involves using atomic absorption spectroscopy or emission spectra to identify the energy levels and electron transitions, which reveal the electronic configuration of the metal ion.

Question 2: List three safety precautions to consider when performing experiments involving electronic measurements of gases or vapours.

Answer: Ensure proper ventilation, wear protective eye equipment, and handle all chemicals with appropriate gloves and lab safety protocols.

Question 1: An element has an atomic number of 15 and its first three ionisation energies are 1680 kJ/mol, 3120 kJ/mol, and 5200 kJ/mol. Explain what these values suggest about its electronic structure.

Answer: The large jump after the third ionisation energy indicates that the element has 3 electrons in its outermost shell, and removing these electrons requires less energy compared to removing electrons from a stable electron configuration.

Question 1: Explain how knowledge of electronic configurations helps in the development of new materials such as semiconductors.

Answer: Understanding electronic configurations allows scientists to manipulate the energy levels and electron arrangements in materials to optimise their electrical properties, leading to the development of efficient semiconductors for use in electronic devices.