Group 1 and group 7 elements both show trends in reactivity.
Reactivity increases down group 1 but decreases down group 7.
Explain these two trends in terms of electrons.
[6 marks]OCR Gateway GCSE Combined Science June 2022 Paper 4
5 questions on this paper's topics
32:001 of 5
Crude oil is separated into fractions in a fractionating column.
Explain how fractional distillation separates crude oil into fractions.
[6 marks]Some metals are added to solutions of metal sulfates.
.1
Which two mixtures react? Tick two boxes.
[2 marks].2
Explain, in terms of ions, why magnesium is more reactive than zinc.
[2 marks]A student has samples of tap water, sea water and rain water.
Plan an investigation to compare the pH and the mass of dissolved solids in the three samples, and to purify the sea water by distillation.
[6 marks]Earth's early atmosphere probably contained a lot of carbon dioxide and little or no oxygen.
.1
Explain how the amount of oxygen in the atmosphere increased.
[2 marks].2
Describe three ways the amount of carbon dioxide in the atmosphere decreased.
[3 marks]