Atom recap

What is the chemical symbol for Sodium?

• Na

• S

• So

• H

Below is the formula for a Chlorine molecule. How many atoms of chlorine are there?

Cl₂

• 1

• 2

• 0

• 3

Which 2 elements make up NaCl?

• Nitrogen & Carbon

• Sodium & Chlorine

• Sodium & Carbon

• Nitrogen & Chlorine

How many atoms are there altogether in the below sulphur dioxide molecule?

SO₃

• 2

• 3

• 4

• 1

Nitrogen and hydrogen react together to form ammonia. Give the word equation for the reaction.

• nitrogen + hydrogen → ammonia

• nitrogen + oxygen → ammonia

• ammonia + hydrogen → Nitrogen

• oxygen + carbon → Carbon Dioxide

Potassium hydroxide reacts with sulfuric acid. Potassium sulfate and water are formed in the reaction.

What are the reactants? Click 2 answers

• Sulphuric Acid

• Potassium hydroxide

• Water

• Potassium sulphate

The total mass of the products is equal to the total mass of the reactants.

This is the definition for which key term in chemistry?

• Decomposition

• Molecules

• Conservation of Mass

• Transpiration

How many different types of atom are in one molecule of a substance that has the formula N₂O₄?

• 2

• 3

• 6

• 8

Challenge - Which numbers correctly fill the gaps to balance this equation?

_Na + Cl₂ → _NaCl

• 1,1

• 2,2

• 4,2

• 2,4

Challenge - how many atoms are in the below molecule?

Mg(OH)₂ 

• 3

• 4

• 5

• 1