P5 Science SA1 2021 — Nanyang

Substance X has a melting point of 40°C and a boiling point of 150°C. In which state will it be at 20°C and 100°C?

Desiree filled 4 different glasses, P, Q, R and S, with 150ml of water at different temperatures. She left them on the kitchen table for 5 hours. Which one of the following arrangements of the glasses shows the amount of water left after 5 hours from the least to the most?

Tom put some ice cubes into a glass of water at room temperature as shown in the diagram below. After 15 minutes, he observed that the ice cubes had disappeared. Which of the following statements correctly explain what had happened to the ice cubes? A The ice cubes lost heat to the water. B The ice cubes gained heat from the water. C The ice cubes changed from the solid state to the liquid state. D The ice cubes changed from the solid state to the gaseous state.

The diagram below shows the water cycle. Which of the following correctly identifies and describes processes X and Y?

Samy made the following observations when he went to the sea. Water: Cloudy with black patches. Fish: Dead and floating on water. Other living things: Not present. Which of the following activities could have caused the observations above? A Removal of litter from the beach. B Oil spills from ships flow into the sea. C Pesticides from farms are washed into the sea. D Untreated sewage water is pumped into the sea.

The following activities involve the use of water. W Washing the car with a hose. X Collecting rainwater to water the plants. Y Leaving the tap running while brushing teeth. Z Flushing the toilet with reused water from washing clothes. Which of the above activities help to conserve water?

The table below shows the weather conditions on 4 different days. Day 1: 25°C, wind Yes. Day 2: 34°C, wind Yes. Day 3: 25°C, wind No. Day 4: 34°C, wind No. Alan conducted an experiment to find out which conditions would allow a wet shirt to dry the fastest. (a) Based on the table above, which day would the wet shirt dry at the fastest rate? Explain your answer. [2] (b) In another experiment, Alan placed 2 different containers, A and B, with 200ml of water each in the open field as shown below. Which container would have more water left after 3 hours? Explain your answer. [2]

Aishah prepared the following set-up. She left it in a room at 32°C for 40 minutes. (a) Explain how the water droplets outside the test tube were formed. [2] After two hours, Aishah observed that the ice cubes had melted completely. She then took out the stopper and left the test tube in the open for one week. One week later, she observed that the test tube was empty. (b) Describe the process that had resulted in the test tube becoming empty. [2]