Redox reactions | Starter Quiz | Oak National Academy

Match the definition with the correct key term.

• ion

• is made up of 2 or more different elements chemically bonded together

• atom

• an atom or group of atoms with a positive or negative charge

• element

• is made up of only one type of atom

• compound

• is the building block of all matter

Answer explanation

Atoms are the building block of all matter; an ion is an atom or group of atoms with a positive or negative charge; an element is made up of only one type of atom; a compound is made up of 2 or more different elements chemically bonded together.

What has been oxidised in this reaction? Zinc oxide + carbon → carbon dioxide + zinc

• zinc oxide

• carbon

• carbon dioxide

• zinc

Answer explanation

The carbon has been oxidised. It has gained oxygen to become carbon dioxide.

What has been reduced in this reaction? Iron oxide + magnesium → magnesium oxide + iron.

• iron oxide

• magnesium

• magnesium oxide

• iron

Answer explanation

The iron oxide loses oxygen to become iron. The iron oxide has been reduced.

What key term is used to describe reactions where a more reactive element takes the place of a less reactive element in a compound?

Answer explanation

Displacement reactions are where a more reactive element takes the place of a less reactive element in a compound.

Match the group in the periodic table with the correct charge on their ions.

• Group 1

• +1

• Group 3

• +2

• Group 6

• +3

• Group 7

• -2

• Group 2

• -1

Answer explanation

Group 1 elements form +1 ions, Group 2 elements form +2 ions, Group 3 elements form +3 ions, Group 6 elements form -2 ions and Group 7 elements form -1 ions.

What is the correct formula and charge of a nitrate ion?

• N₃ᐨ

• N₃ᐨ²

• NO₃ᐨ

• NO₃ᐨ²

Answer explanation

The correct formula and charge of a nitrate ion is NO₃ᐨ