Physical Changes Level 3 Stefan is on holiday in the mountains. It is snowing. (a) (i) Choose words from the box to complete the sentence below. solid liquid gas A snowflake falls on Stefan s nose and melts. When the snowflake melts, it changes from a... to a.... (ii) Snow that falls on the ground melts slowly. Snow that falls on Stefan s nose melts very quickly. Give a reason for this.... (iii) In his hotel, Stefan sees some changes. Are the changes below reversible? Write yes or no. ice melting... wood burning... toasting bread...
(b) (i) Stefan is snowboarding. Gravity acts on Stefan. On the diagram below, draw an arrow to show the direction of the force of gravity. (ii) When Stefan wants to slow down, he pushes one edge of the snowboard into the snow. What force between the board and the snow makes him slow down?...
(a) Draw a line from each change of state to the correct name. Draw only four lines. 3 marks (b) Kate made some ice cubes from pure water. She used a sensor to measure the temperature of the ice. What temperature will the sensor show when the ice is melting?... C
(c) Kate made some more ice cubes from salt solutions. She used a different amount of salt in each ice cube. The table shows the temperature at which the ice cubes melted. mass of salt in each ice cube (g) temperature ice cube melted ( C) 5 4 10 8 15 11 20 15 Look at the table above. As the mass of salt increased, what happened to the temperature at which the ice cube melted?... (d) In very cold weather a mixture of salt and sand is spread on roads. Why are salt and sand used? Tick the two correct boxes. 2 marks
Sam made a model cat. He mixed modelling powder with water. He poured all of the mixture into a mould. He covered the mould with plastic film so that water could not evaporate. (a) (i) After 10 minutes, Sam removed the model cat from the mould. Sam had mixed 40 g of modelling powder with 12 g of water. What was the mass of the model cat?... g (ii) Complete the sentence below using words from the list. gas liquid solid vapour After 10 minutes, the mixture in the mould changed from a... into a... 2 marks
(b) Sam attached a small magnet to the model cat. The magnet was attracted to the fridge door. What metal are magnets made from?... (c) Sam made another model, B. He attached a small magnet to model B. (i) Sam placed model A next to model B. The magnets attracted each other. Label the poles on the magnet on model B Use the letters N and S. (ii) Sam then turned the magnet on model A around. What would happen to model B?... 2 marks
(a) Jenny put a bottle of fizzy drink on a balance. She removed the bottle-top, and the drink began to fizz. She left the open bottle of drink and the bottle-top on the balance for five days in a warm room. at the start five days later Five days later the drink was no longer fizzy. It s mass had decreased and the level of the liquid had gone down. (i) Look at the drawings of the balance. Work out the decrease in mass after five days.... g (ii) The fizzy drink contained sugar, colouring, a gas and water. The mass decreased because two of these substances were lost into the air. Which two substances were lost into the air? 1.... 2....
(b) The sugar, colouring and the gas were all dissolved in the water. Which word describes the water? Tick the correct box. alkali indicator solute solvent
Level 4 Kala recorded temperatures using a datalogger and three temperature sensors, P, Q and R. The ends of the sensors were covered with gauze. P was kept dry. Q was dipped in water for 2 seconds and then taken out. R was dipped in ethanol for 2 seconds and then taken out. Every five minutes, the datalogger recorded the temperatures of the sensors. time, in min temperature of sensor P, in C temperature of sensor Q, in C temperature of sensor R, in C 0 20 20 20 5 20 18 16 10 20 17 12 15 20 17 20
(a) What was the temperature of the room at the beginning of Kala s experiment?... C (b) Describe how the temperatures of sensor Q and sensor R changed. sensor Q...... sensor R...... 2 marks (c) The next day the gauze on sensor Q felt dry. What had happened to the water on the gauze?...
John dropped a glass bottle of blue copper sulphate crystals. The bottle broke and glass was mixed with the crystals. (a) Suggest how John or a teacher could clear up the mixture safely, without cutting themselves....... (b) Mari said, You can separate the glass from the copper sulphate crystals using a sieve. Most of the crystals went through the sieve. Some of the glass went through as well. Why did some of the crystals and pieces of glass stay in the sieve?... (c) John tried another way to separate the glass from the blue copper sulphate crystals. He put the mixture into water and stirred it. The water turned blue. Why did the water turn blue?... (d) Very carefully, he poured some of the blue liquid into a dish and gently heated it. The volume of the liquid decreased. Why did the volume decrease?... (e) John put the dish by a window. The next day there was no liquid left. What would be left in the dish?...
Emma dissolved some salt in some water to make salt water. (a) Which words in the list below describe the salt, the water and the salt water? Write the correct words in the table. 3 marks solution solute sediment filtrate solvent (b) What two things could Emma do to make the salt dissolve more quickly? 1.... 2.... 2 marks (c) Emma dissolved 5 g of salt in 50 cm3 of water. Now she wants to make some salt water which is only half as concentrated. What should she do? Tick the correct box.
Becky puts one tea bag in a beaker and adds 50 cm3 of warm water. She stirs the liquid slowly. Every 15 seconds she takes out 2 cm3 of the liquid and measures how dark it is. (a) Which graph, A, B or C, shows how the colour of the liquid changes?... (b) (i) Becky takes out 2 cm3 samples of the liquid each time. Why must she always put the sample back after she has tested it?... (ii) What piece of apparatus can she use to measure the volume of the 2 cm3 samples of liquid?... (iii) Suggest two ways Becky could make the tea dissolve more quickly. 1...... 2...... 2 marks