The Periodic Table

Which of these substances has/have a stable electronic configuration? Check all that apply.

• Helium

• Argon

• Nitrogen gas

• Krypton

Answer explanation

Nitrogen is a diatomic molecule with a stable electronic configuration. The other gases are all monatomic noble gases.

Which of these is not a property of noble gases?

• Colourless

• Odourless

• Flammable

• Gas at room temperature

Answer explanation

Being inert, noble gases will not readily react with oxygen for combustion reactions.

When compared to Group 1 metals, the transition metals are...

• harder

• softer

When compared to Group 1 metals, the transition metals have...

• higher melting points

• lower melting points

When compared to Group 1 metals, the transition metals are...

• less reactive

• more reactive

Platinum and gold are transition metals that are used in wedding rings. Which 2 properties makes them useful for this?

• These metals have low densities

• These metals do not react with water

• These metals do not react with oxygen

• These metals have low melting points

Why do the boiling points of the noble gases increase down Group 18?

• The covalent bonds become stronger

• The weak forces of attraction between particles become stronger

• The ionic bonds become stronger

• The metallic bonds become stronger

Answer explanation

Noble gases are monatomic. There are weak forces of attraction between atoms (as noble gases are made of atoms, not molecules). As these weak forces are the ones overcome during a change of state, it must be that they get stronger down Group 18, if the data shows that the boiling points get higher down Group 18.

Which of these metals have ions with variable oxidation states (i.e. charges)?

• Iron

• Zinc

• Sodium

• Copper

• Magnesium

Answer explanation

Copper can form the copper(I) and copper(II) ions; iron can form iron(II) and iron(III) ions. The other metals are not transition metals; they form ions with a single oxidation state (i.e. charge).

• A

• B

• C

• D

• A

• B

• C

• D