Question 1: Noble gases are elements in Group 0 of the periodic table characterised by their very low reactivity. This is due to their full outer electron shells, which make them stable and unlikely to form chemical bonds.

Answer: Noble gases have full outer electron shells, making them very stable and chemically inert.

Question 1: Define the term 'monatomic' as it relates to noble gases.

Answer: Monatomic means consisting of single atoms, which is characteristic of noble gases.

Question 2: Explain why noble gases have very low boiling points compared to other elements in the same period.

Answer: Noble gases have weak van der Waals forces between their atoms, resulting in low boiling points.

Question 1: The boiling points of noble gases are as follows: Helium: -269°C, Neon: -246°C, Argon: -186°C, Krypton: -153°C, Xenon: -108°C, Radon: -62°C. Analyse the trend in boiling points across the group and explain the pattern.

Answer: The boiling points increase down the group due to increased atomic size and greater van der Waals forces, which require more energy to overcome.

Question 2: Based on the data provided, which noble gas would be most suitable for use in a cryogenic liquid, and why?

Answer: Helium, because it has the lowest boiling point, making it ideal for extremely low temperatures.

Question 1: Calculate the energy in joules required to liquefy 1 mol of Neon (boiling point at -246°C). Use the latent heat of vaporisation for Neon: 1.7 kJ/mol.

Answer: 1700 J

Question 2: If 2 mol of Argon are cooled from room temperature (25°C) to its boiling point (-186°C), estimate the energy lost assuming a specific heat capacity of 0.52 J/g°C and molar mass of 39.95 g/mol. (Show your working.)

Answer: Work: Energy lost = m × c × ΔT = n × M × c × ΔT = 2 mol × 39.95 g/mol × 0.52 J/g°C × (25 - (-186))°C = approximately 6730 J

Question 1: Describe a basic experimental setup to collect data on the reactivity of noble gases with halogens, including variables to control and safety precautions.

Answer: The setup would include a sealed reaction chamber, controlled temperature and pressure, and detection methods such as spectroscopy. Variables to control include temperature, pressure, and gas concentrations. Safety precautions involve proper handling of halogens, use of fume hoods, and protective equipment.

Question 1: Explain why Xenon is used in certain types of flashlights and lamps.

Answer: Xenon emits bright, intense light when ionised, making it suitable for high-intensity flashlights and photographic flashes.

Question 2: Discuss the advantages of using Helium in MRI (Magnetic Resonance Imaging) machines.

Answer: Helium is used because it remains liquid at very low temperatures, providing efficient cooling of MRI magnets, which enhances image quality and reduces energy costs.