Primary 3 Science · Answers and explanations

Diversity of Materials: Investigation Practice

Use this page to check the worksheet together. Talk about why each answer is right. Total: 20 marks.

Section A · Multiple choice 8 marks

1. Look at the bar chart. Which material is the strongest?1 mark

(A) Paper(B) Cloth(C) Foil(D) Plastic sheet

Answer: (B) ClothCloth held the most weight (180 g), so it is the strongest.

2. Look at the bar chart. How many more grams did the cloth hold than the paper?1 mark

(A) 140 g(B) 120 g(C) 60 g(D) 220 g

Answer: (A) 140 g180 - 40 = 140 g.

3. Look at the float or sink table. Which list has only objects that sank?1 mark

Float or sink test

Object	Made of	Size	Result in water
Wooden block	wood	big	floats
Glass bead	glass	small	sinks
Bottle cap	plastic	small	floats
Iron nail	metal	medium	sinks
Ceramic tile	ceramic	big	sinks

(A) wooden block, glass bead, iron nail(B) bottle cap, iron nail, ceramic tile(C) glass bead, bottle cap, ceramic tile(D) glass bead, iron nail, ceramic tile

Answer: (D) glass bead, iron nail, ceramic tileThe three that sank are the glass bead, the iron nail and the ceramic tile.

4. Look at the waterproof test. Which sheet is waterproof?1 mark

Waterproof test (tissue placed under each sheet)

Sheet	What happened to the drop	Tissue under sheet
P	stays as a drop on top	dry
Q	soaks into the sheet	dry
R	water slowly passes through small holes	wet
S	soaks into the sheet	wet

(A) Q(B) R(C) P(D) S

Answer: (C) POnly P kept the water on top and kept the tissue dry. Q and S soaked water up. R let water pass through.

5. Look at the light test. Which sheet is opaque?1 mark

Light test

Sheet	A torch bulb seen through the sheet
M	clearly
N	as a blurry glow
O	not at all

(A) M(B) O(C) N(D) None of them

Answer: (B) OThe torch bulb could not be seen at all through O, so no light passes through. It is opaque.

6. Zara wants to find out which material is the strongest by hanging weights. Which one thing should she keep the SAME for every strip?1 mark

(A) The size of the strip(B) The material of the strip(C) The type of material she tests(D) Which strip she tests first

Answer: (A) The size of the stripIn a fair test, only the material is changed. The size of the strip must stay the same.

7. Which property is the MOST important for a material used to make a raincoat?1 mark

(A) Transparent(B) Floats on water(C) Opaque(D) Waterproof

Answer: (D) WaterproofA raincoat must not absorb water or let it pass through, so it must be waterproof.

8. A hair band must stretch and bend without breaking. Which property does the material need?1 mark

(A) Transparent(B) Waterproof(C) Flexible(D) Sinks in water

Answer: (C) FlexibleBending without breaking is called being flexible.

Section B · Show what you know 12 marks

9. Look at the bar chart. Mia hangs a load of 100 g on each strip. Name the materials that would tear.2 marks

Answer: Paper and foilPaper held only 40 g and foil only 60 g, which are less than 100 g, so they tear. Plastic sheet (120 g) and cloth (180 g) hold it. 1 mark for each correct material.

10. Look at the float or sink table. Ben says, "Small things float and big things sink." Is he right? Use the table to explain.2 marks

Float or sink test

Object	Made of	Size	Result in water
Wooden block	wood	big	floats
Glass bead	glass	small	sinks
Bottle cap	plastic	small	floats
Iron nail	metal	medium	sinks
Ceramic tile	ceramic	big	sinks

Answer: No. The small glass bead sank but the big wooden block floated (or similar).Floating depends on the material, not the size. 1 mark for no, 1 mark for evidence from the table.

11. Look at the waterproof test. Sheets Q and R are both NOT waterproof, but they fail in different ways. Explain how each one fails.2 marks

Waterproof test (tissue placed under each sheet)

Sheet	What happened to the drop	Tissue under sheet
P	stays as a drop on top	dry
Q	soaks into the sheet	dry
R	water slowly passes through small holes	wet
S	soaks into the sheet	wet

Answer: Q absorbs (soaks up) the water. R lets the water pass through.Q: the drop soaked in, so Q absorbs water. R: the tissue became wet, so water passed through. 1 mark each.

12. Look at the light test. Mia wants a window cover that lets light in but stops people outside from seeing clearly into the room. Which sheet should she use? Give a reason.2 marks

Light test

Sheet	A torch bulb seen through the sheet
M	clearly
N	as a blurry glow
O	not at all

Answer: Sheet N. It lets some light through but things look blurry (it is translucent).1 mark for N, 1 mark for the reason: some light passes through and the view is unclear.

13. Look at Ali's test. He wants to find which material is stronger, but his test is not fair. State what is wrong and how he can fix it.2 marks

Ali's strength test

	Material	Width	Length	Weights added
Strip 1	foil	2 cm	10 cm	one at a time
Strip 2	cling wrap	4 cm	10 cm	one at a time

Answer: The strips have different widths (2 cm and 4 cm). He should use strips of the same width.1 mark for width being different, 1 mark for using the same width. Length and weights added are already the same.

14. Look at the table. Sam needs a squeezable water bottle that is waterproof and lets him see how much water is left. Which material should he choose? Give two reasons.2 marks

Properties of four materials

Material	Waterproof?	Flexible?	Transparent?
Clear plastic	yes	yes	yes
Glass	yes	no	yes
Cloth	no	yes	no
Metal	yes	no	no

Answer: Clear plastic. It is waterproof, flexible (squeezable) and transparent.1 mark for clear plastic. 1 mark for two correct reasons from the table (no mark for the reasons if only one is given). Glass is not flexible; cloth is not waterproof or transparent; metal is not flexible or transparent.

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