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] 3 marksFoundation
Burning fuels can release several pollutants.
.1Which pollutant is a toxic gas that reduces the blood's ability to carry oxygen?
[1 mark] .2Which pollutant causes global dimming?
[1 mark] .3Name the environmental problem caused by sulfur dioxide dissolving in rain water.
[1 mark] 3 marksFoundation
Chemical reactions can transfer energy to or from the surroundings.
.1Which two reactions are exothermic? Tick two boxes.
[2 marks] .2Give one everyday use of an endothermic reaction.
[1 mark] 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
Mendeleev published a periodic table in 1869. He left gaps in his table.
.1Why did Mendeleev leave gaps in his table?
[1 mark] .2Mendeleev placed iodine after tellurium, although iodine has a smaller atomic weight.
Explain why.
[2 marks] .3What is the modern periodic table arranged by?
[1 mark] 