Matter and Materials Quiz

Two bottles of water are kept in different environments: Bottle X is kept in a freezer at -10°C. Bottle Y is kept in a freezer at -20°C. After 2 hours, which of the following statements is correct?

1. Bottle X froze, but Bottle Y stayed liquid.
2. Bottle Y froze faster with smaller ice crystals.
3. Bottle X froze slower, forming larger ice crystals.
4. Both froze the same way, temperature doesn’t matter.

Answer: (b) Bottle Y froze faster with smaller ice crystals.

The graph shows temperature changes of water over time. Which section of the graph represents boiling?

1. The slope AB
2. The horizontal line BC
3. The horizontal line DE
4. The slope after DC

Answer: (c) The horizontal line DE

A student notices that when she bends a metal spoon slightly, it comes back to its original shape. She says, "This means the spoon is not a solid because I could bend it." Why is her conclusion incorrect?

1. Some solids are flexible but still keep their overall shape and volume.
2. The spoon is actually a liquid inside a shell.
3. Solids can never be bent or shaped.
4. Solids don’t exist in everyday objects.

Answer: (a) Some solids are flexible but still keep their overall shape and volume.

Who among the following made the correct statement? Aria: “A solid cannot flow because its particles are packed so tightly that they can only vibrate in place.” Leo: “A solid flows slowly because its particles move randomly and have large gaps between them.”

1. Aria is correct but Leo is incorrect.
2. Leo is correct but Aria is incorrect.
3. Both Aria and Leo are correct.
4. Both Aria and Leo are incorrect.

Answer: (a) Aria is correct but Leo is incorrect.

You drop a fizzy tablet into water and observe bubbles. The tablet dissolves and releases gas. Which conclusion is best?

1. Only a physical change occurs because it dissolves.
2. It is a physical change because no heat is involved.
3. It is a reversible physical change.
4. It is a chemical change because gas formation and a new substance occur.

Answer: (d) It is a chemical change because gas formation and a new substance occur.

A factory releases a liquid mixture of chemicals and water. They want to recover pure water and reuse it. Which separation technique is best and why?

1. Filtration, because it removes all chemicals
2. Sedimentation, because chemicals will settle down
3. Evaporation, because it leaves chemicals behind and collects water vapor
4. Distillation, because it separates substances based on boiling points

Answer: (d) Distillation, because it separates substances based on boiling points

Look at the steps in separating technique. What is the best missing step (X)?

1. Use evaporation
2. Use magnet to attract seeds
3. Use sieve to separate components by size
4. Let seeds float and decant

Answer: (c) Use sieve to separate components by size

A science lab is given three unknown white powders: Powder A disappears completely in water. Powder B forms a cloudy mixture and settles after 1 hour. Powder C bubbles when vinegar is added. Which pair of separation or identification methods would best classify all three correctly?

1. Filtration and evaporation
2. Evaporation and sedimentation
3. Sedimentation and crystallisation
4. Filtration and chemical reaction testing

Answer: (d) Filtration and chemical reaction testing

Study the given table and select the option that best represents the headings X, Y, and Z:. Features X Y Z Can be separated by filtration Yes No No Can be separated by evaporation No Yes No Can be separated by sedimentation and decantation No No Yes

1. X – Sand and Water, Y – Salt solution, Z – Muddy water
2. X – Salt solution, Y – Muddy water, Z – Oil and Water
3. X – Muddy water, Y – Salt solution, Z – Sand and Water
4. X – Oil and Water, Y – Salt solution, Z – Sand and Water

Answer: (a) X – Sand and Water, Y – Salt solution, Z – Muddy water

Four students were asked to identify the correct separation technique for an oil-water mixture. Who is correct? Alex: Filtration is the best method to separate oil from water. Maria: Decantation can be used to separate oil floating on water. John: Sedimentation helps to separate oil and water. Sophia: Distillation separates oil from water because they have different boiling points.

1. Only Maria
2. Maria and Sophia
3. Alex and John
4. Only Alex

Answer: (b) Maria and Sophia