4º 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 FORCES

4º NS STUDENT´S BOOK (solutions)

PAGE 69

SOLUTIONS

1 Sorting plastics and paper because they can be reused or recycled.

2 Plastic, paper (various background materials, such as cotton, wood, metal, glass).

3 Pupils’ own answers.

4 Pupils’ own answers.

5 You apply a force to the material. Depending on how resistant or elastic a material is, it can stretch, break or change shape.

6 Pillows, house, window, metal, toys.

PAGE 70

SOLUTIONS

1 a.false; b.false; c.false; d.true

PAGES 72, 73

SOLUTIONS

1 Mass is the amount of matter an object contains; Volume is the space an object occupies.

2 A piece of granite; a balance.

3 75 ml.

4 Pupils’ own answers.

5 Mass can be measured on a scale or balance. Volume can be measured by a measuring cup or cylinder.

6 The first object has a density of 4 kg/l; If the volume changes to 4 l, it will have a higher density of 5 kg/l.

7 Pupils’ own answers.

PAGES 74, 75

SOLUTIONS

1 Manufactured: Kevlar®, concrete, steel, aluminium, plasticine; natural: granite, marble, silk, soil, oil, hemp.

2 Pupil’s own answers.

3 Diamond; used for jewellery and cutting other materials.

4 Hardness refers to malleability whereas resistance refers to the durability of a material. A material can be hard but not resistant and vice versa.

5 The scientist talks about thermal conductivity; The example is a metal spoon; The spoon conducts heat and becomes hot.

6 Pupil’s own answers.

PAGES 76, 77

SOLUTIONS

1 Magnetic objects with the same polarity attract each other while opposite poles repel.

2 The theory of gravity.

3 Pupils’ own answers.

4 Weight is a measurement of the force of gravity acting on an object.

5 First gravity and then friction when the parachute opens.

6 Pupils’ own answers.

7 Pupils’ own answers.

PAGES 78, 79

SOLUTIONS

1 1.hemp; 2.bamboo; 3. cork; 4.biocomposites.

2 Pupils’ own answers.

3 Fuel – biocomposites; clothes – bamboo, cork, hemp; medicine – hemp

4 Pupils’ own answers.

5 Pupils’ own answers.

6 Pupils’ own answers.