Which pair of properties best describes the elements in group 18 of the periodic table?

• A. Chemically inert and gases at room temperature
• B. Highly reactive and solid at room temperature
• C. Form colored compounds and have variable oxidation states
• D. Good conductors of electricity and form basic oxides

Answer: (A)

Verified step by step guidance

1. Identify the group number and position of the elements in question: Group 18 of the periodic table is known as the noble gases group.
2. Recall the general properties of noble gases: They are known for their lack of chemical reactivity due to having a full valence electron shell, making them chemically inert or very unreactive.
3. Consider the physical state of these elements at room temperature: Most noble gases exist as gases under standard conditions (room temperature and atmospheric pressure).
4. Evaluate the given options against these known properties: Noble gases are chemically inert and gases at room temperature, which matches the first option.
5. Confirm that other options do not fit: Noble gases are not highly reactive solids, do not typically form colored compounds or variable oxidation states, and are poor conductors of electricity and do not form basic oxides.