Question 1: Noble gases are a group of elements located in Group 0 of the periodic table. They are known for their very low reactivity due to their full outer electron shells. Common noble gases include helium, neon, argon, krypton, xenon, and radon.

Answer: Noble gases are elements in Group 0 of the periodic table characterized by full outer electron shells and low reactivity.

Question 1: Explain why noble gases are generally unreactive despite having electrons available for bonding.

Answer: Because they have full outer electron shells, noble gases are stable and do not readily form bonds with other elements.

Question 2: Describe how atomic radius changes as you move down Group 0 in the periodic table.

Answer: The atomic radius increases as you move down Group 0 because additional electron shells are added.

Question 3: Which noble gas is most commonly used in neon signs, and why?

Answer: Neon is used because it emits a bright red-orange glow when an electric current passes through it.

Question 1: Identify two common applications of argon and explain why argon is suitable for these uses.

Answer: Argon is used in welding and in light bulbs because it is inert, preventing oxidation, and has a high density that displaces air.

Question 2: Describe a safety precaution that should be taken when handling radon in an industrial setting.

Answer: Radon is radioactive; therefore, proper ventilation and protective equipment are necessary to prevent inhalation.

Question 1: What is the main reason that noble gases do not usually form chemical bonds?

Answer: Because they already have a full outer electron shell, reducing their tendency to gain or lose electrons.

Question 2: Explain how the full outer electron shell of noble gases affects their chemical reactivity.

Answer: A full outer shell makes noble gases chemically stable and unlikely to react with other elements.

Question 1: Calculate the atomic radius of argon if its atomic number is 18 and the radius of neon (atomic number 10) is approximately 60 pm. Assume a linear trend for simplicity.

Answer: Using the trend that radius increases by about 12 pm per additional electron shell, the radius of argon is approximately 90 pm.

Question 2: Given that the boiling point of helium is -269°C and that of xenon is -108°C, describe the trend in boiling points among noble gases and explain the reason.

Answer: Boiling points increase down the group because of greater atomic mass and stronger London dispersion forces.

Question 1: Describe a simple experiment to demonstrate the inertness of noble gases such as helium or neon.

Answer: A student can introduce noble gases into a sealed container with reactive substances, noting that no reaction occurs, demonstrating their inertness.

Question 2: List two safety precautions that must be taken when working with compressed noble gases in a laboratory.

Answer: Ensure proper ventilation and use pressure regulators to prevent over-pressurization.