3º NS Unit 5 – MATTER AND ENERGY (Student´s Book solutions)

HOMEWORK for the weekend:

1. First, check the solutions of the exercises in the books of N.S. (Student´s Book and Activity Book).

2. Then, do the TEST.

UNIT 5 Natural Science – MATTER AND ENERGY

3º NS STUDENT´S BOOK (solutions)

PAGE 77

SOLUTIONS

1 Glass, metal, plastic, paper, fabric, etc.

2 Plastic, metal, glass, paper, etc.

3 Pupils' own answers.

4 Plastic, glass, paper, metal, fabric.

5 Book (paper, card, glue); window (glass, plastic, wood or metal); water bottle (plastic, glass or

metal).

PAGE 78

SOLUTIONS

1 a.waterproof; b.fragile; c. flexible; d.rough

PAGE 81

SOLUTIONS

1 Possible answers: desks, chairs, rubbers, etc.

2 River (liquid)

iceberg (solid)

snow (solid)

vapour (gas)

rain (liquid)

3 Definite shape (solid)

definite volume (solid, liquid).

PAGES 82, 83

SOLUTIONS

1 Natural thermal energy is the sun; Artificial thermal energy includes candles, torches,

heaters, etc.

2 Evaporation (liquid becomes gas); melting (solid becomes liquid); freezing (liquid becomes solid).

3 Electrical energy can pass through a conductor easily. Electrical insulators do not allow

electricity to pass through.

4 People singing; the sun; people running.

PAGES 84, 85

SOLUTIONS

1 A mixture contains two or more types of matter.

2 1.solid, you can see the different types of matter; 2. liquid and solid, you can see the

different types of matter; 3.liquid, you cannot see the types of matter; 4.solid, you can see the

different types of matter; 5.liquid, you cannot see the different types of matter; 6.solid, you

can see the different types of matter.

3 Smoothies, salads, etc.

4 Sand from water (filtering); sand from pebbles (sieving); salt from seawater (evaporating).

PAGES 86, 87

SOLUTIONS

1 1.b; 2.d; 3. a; 4. c. Container 3 can take many types of unrecyclable materials.

2 Orange containers recycle cooking oil. Brown containers recycle plant and vegetable waste.

3 Pupils' own answers.

4 To reduce waste, conserve natural resources, etc.

5 Pupils' own answers.

6 1. cotton, or plastics recycled into polyester; 2. rubber and recycled plastics; 3.paper or card, and recycled plastics; 4.glass.

7 Recycled paper, bags, clothes, jewellery, etc.

8 Pupils' own answers.

9 Pupils' own answers.

PAGE 88

SOLUTIONS

1 Matter (states and physical changes)

States (liquid, solid, gas)

Physical changes (change of shape, change of state)

Change of state (freezing, evaporation, melting)

2 a. states; solid b. physical c. insulators d. thermal; light e. mixture f. filtering

3 a. filtering b. evaporation c. sieving d. filtering

PAGE 89

SOLUTIONS

4 - 1. c; 2.a; 3. b

5 - Pupil A

a. What are the three states of matter? (Solid, liquid, gas)

b. What is the opposite of rough? (Smooth)

c. How can you separate two solids? (Sieving)

Pupil B

a. Which materials can you recycle? (Glass, paper, plastic, metal, fabric, oil, vegetable, matter)

b. What is an electrical insulator? (A material which does not allow an electrical current to pass through)

c. What is the opposite of rigid? (Flexible)