4 marksFoundation
A teacher adds a small piece of lithium to a trough of water containing universal indicator.
.1Give two observations the students would see.
[2 marks] .2Complete the word equation: lithium + water → lithium hydroxide + ______
[1 mark] .3The teacher repeats the demonstration with potassium. Predict how the reaction compares.
[1 mark] 4 marksFoundation
Magnesium reacts with oxygen to form magnesium oxide, an ionic compound.
The electron structure of magnesium is 2,8,2 and of oxygen is 2,6.
.1Describe what happens to the electrons when magnesium reacts with oxygen.
[2 marks] .2What are the charges on the ions in magnesium oxide?
[1 mark] .3Name the type of force that holds the ions together.
[1 mark] 4 marksFoundation
A student adds marble chips to hydrochloric acid and collects the carbon dioxide in a gas syringe.
.1Calculate the mean rate of reaction in the first 30 seconds.
[2 marks] .2Give the earliest time in the table by which the reaction had stopped.
[1 mark] .3Describe how the rate changes during the reaction.
[1 mark] 2 marksFoundation
Dry air is a mixture of gases.
.1Which gas makes up about four-fifths of the air?
[1 mark] .2A classroom holds 200 m³ of air. Calculate the approximate volume of oxygen in the room, using oxygen as one-fifth of the air.
[1 mark] 4 marksFoundation
Some substances are listed below.
Copper, carbon dioxide, air, sodium chloride.
.1Which substance is an element?
[1 mark] .2Which substance is a mixture?
[1 mark] .3Give the number of different elements in the formula
CaCO3. .4A student has a mixture of sand and water. Choose the best method to get the sand.
[1 mark] 