Across

    1  The lightest inert gas. (6)

    4  The element we need to breathe. (6)

    5  Alkaline metal in table salt. (6)

    7  Inert gas used to make bright city lights. (4)

    8  2nd place in the Olympics. (6)

  10  An important element in bones. (7)

  13  A radioactive element often used in nuclear power stations. (7)

  14  Poison gas in WWI. (8)

  15  A famous poison that turns your tongue black. (7)

  17  A metal sought after during the Klondike. (4)

  18  The element diamonds are made from. (6)

  19  This metal is used along with carbon to make steel. (4)

 

Down

    2  Heavy metal used in paints, batteries, and radiation shields. (4)

    3  The most common element in the universe. (8)

    6  A liquid metal that was used in thermometers. (7)

    7  Most common element in the earth's atmosphere. (8)

    9  A component of gunpowder that smells like rotten eggs. (7)

  11  A metal used in foil. (World Spelling) (9)

  12  A metal used in wires. (6)

  15  The most common inert gas in the atmosphere. (5)

  16  Element used to make semi-conductors (computer chips). (7)