Give three elements of Group 18.

• Helium

• Neon

• Argon

• Lithium

• Sodium

All inert gases exist as _______________ gases at room conditions.

The helium atom has 2 valence electrons. These arrangement is called a _____________ electron arrangement.

• octet

• duplet

Atomic elements of Group 18, other than helium, have ___ valence electrons.

• 1

• 2

• 8

• 7

__________ is used to fill weather balloons.

Group 18 elements are also known as noble gases or ______ gases.

Elements of group 18 have the following physical properties:

• Have low melting and boiling point

• Have high melting and boiling point

• Conduct electricity

• Do not conduct electricity

• Have low density

Group 1 in the Periodic Table of Elements is made up of __________ metals.

Elements of group 1 have the following physical properties:

• They cannot conduct electricity

• They are soft and shiny solids

• Have low density

• They cannot conduct heat

All alkali metal atoms have ______ valence electron.