* Consider the state of matter at room temperature: Most elements are solids at room temperature (around 25 degrees Celsius).
* Focus on the noble gases: Noble gases (Helium, Neon, Argon, Krypton, Xenon, Radon) are already gases at room temperature due to their weak interatomic forces.
* Think about boiling points: The boiling points of noble gases increase as you go down the group.
At 500 degrees Celsius, the following elements will definitely be gases:
* Helium (He) - Boiling point: -268.9 °C
* Neon (Ne) - Boiling point: -246.1 °C
* Argon (Ar) - Boiling point: -185.7 °C
* Krypton (Kr) - Boiling point: -153.4 °C
* Xenon (Xe) - Boiling point: -108.1 °C
Radon (Rn) might also be a gas at 500 degrees Celsius, but it's radioactive and not readily available.
Therefore, all the noble gases from Helium to Xenon are gases at 500 degrees Celsius.
