1. Until the early 1960s the group 8A elements were called the inert gases; before that they were called the rare gases. The term rare gases was dropped after it was discovered that argon accounts for roughly 1% of Earth's atmosphere.

(a) Why was the term inert gases dropped?

(b) What discovery triggered this change in name?

(c)What name is applied to the group now?

2. (a) Why does xenon react with fluorine, whereas neon does not?

(b) Using reference sources such as the CRC Handbook of Chemistry and Physics or online sources, look up the bond lengths of Xe-F bonds in several molecules. How do these numbers compare to the radii of the elements?