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Group IA elements have the outer electron configuration:

• 1 ns2 np1
• 2 ns2 np5
• 3 ns2
• 4 ns1

Which gas is released when sodium reacts with water?

• 1 Nitrogen
• 2 Chlorine
• 3 Hydrogen
• 4 Oxygen

The most abundant element in the Earth's crust is:

• 1 Iron
• 2 Silicon
• 3 Aluminium
• 4 Oxygen

Halogens exist as:

• 1 Diatomic molecules
• 2 Monatomic gases
• 3 Metallic solids
• 4 Triatomic molecules

Noble gases are unreactive because they have:

• 1 High density
• 2 Complete outer shells
• 3 Large size
• 4 One outer electron