Noble Gases

Colorless, odorless gases in Group 18. Extremely unreactive due to complete outer electron shells.

Discovery Period: Late 19th to early 20th century (1868-2006)

Characteristics

• • Completely filled outer shell
• • Extremely low reactivity
• • Colorless and odorless
• • Low boiling points
• • Exist as monatomic gases
• • Used in lighting and welding