Chemistry Past Paper PDF

1 1 The diagram shows an atom of hydrogen. The nucleus contains only one particle. (a) Complete the labels on the diagram...................................... nucleus containing.............................................................

1 1 The diagram shows an atom of hydrogen. The nucleus contains only one particle. (a) Complete the labels on the diagram...................................... nucleus containing.......................................................... (b) Write down the chemical symbol for hydrogen.  2 2 Potassium is an element in Group 1 of the Periodic Table. (a) Look at the word equation. potassium + water potassium hydroxide + hydrogen Write down the name of one product of this reaction. (b) Look at the order of the elements in Group 1 of the Periodic Table. Li lithium Na sodium potassium Rb rubidium Cs caesium Fr francium (i) What is the chemical symbol for potassium? Circle the correct answer. K N Na P Po (ii) What do these elements in Group I have in common?.......................................................... (c) The chemical symbol for lithium is Li. The formula for water is H2O. The formula for lithium hydroxide is LiOH. Which of these substances is an element? Choose from lithium, water or lithium hydroxide...................................................... Explain your answer.................................................................................................................................  3 3 The diagram shows the structure of a boron atom. = particle Y = particle Z a. Name particles Y and Z. particle Y particle Z b. In the Periodic Table, Boron is found in (i) Group..................................................... Reason.................................................. (ii) Period.................................................... Reason.................................................  4 4 Angelique measures the temperature of three samples of water. The diagrams show her results. 0 40 10 –10 30 0 –10 –20 20 thermometer A thermometer B thermometer C Record the temperature of each thermometer in the table. thermometer temperature in °C A B C Mia collects three liquids found in her kitchen. coffee tea cleaning fluid Mia then makes this statement about the substances. The three liquids are acids. (a) Mia’s friend Carlos tells her she has no evidence for her statement. Why is it important to have evidence to back up a scientific statement? (b) Describe how Mia uses an indicator to collect evidence for her statement. Include the  name of the indicator  result she gets if the liquids are acids. Indicators can be used to test for acids, alkalis and neutrals. Look at the colours of three different indicators. result with acid alkali neutral indicator A red blue purple indicator B red yellow orange indicator C colourless pink colourless Aluminium sulfate is used in water purification. Zaon tests aluminium sulfate solution with three indicators A, B and C. Here are his results. result with indicator A indicator B indicator C aluminium sulfate red red colourless Suggest a pH value for aluminium sulfate solution?................................................................................................................................................. Explain your answer.............................................................................................................................................. Colin puts two identical trays containing soil and seeds in the classroom. He gave each tray the same amount of water every day. One tray, A, was left beside a window in the light and the other, B, in a dark cupboard. Both trays were at the same temperature. The diagram shows the young plants two weeks after planting. A B (a) Write down two differences that you can see between the plants in trays A and B. 1....................................................................................................................................... 2................................................................................................................................... (b) Tick (9) two boxes to show the correct facts about light. light is a form of energy light is given out by the window light is the same as heat the Sun is a light source the moon is a light source (c) These plants need the soil to be at neutral pH. Write down the pH of the soil when it is neutral. pH....................