Question

1. synthesize information the noble gases in group 18 were some of the last natural elements to be discovered. why do you think this is so?

Explanation:

Noble gases are inert due to full - valence electron shells. They do not easily react with other substances, making them hard to detect through common chemical reactions used in early element discovery. They are also present in low concentrations in the atmosphere.

Answer:

Noble gases are inert with full - valence shells, present in low atmospheric concentrations, and do not react easily, thus were among the last to be discovered.