chapter 2

Question 1

what are some types of materials

Answer 1

metal
ceramic
glass
fibres
plastic

Question 2

some common physical properties

Answer 2

electrical conductivity
thermal conductivity
melting and boiling points

Question 3

why is the base of a flying pan made of metal?

Answer 3

metal has high melting point and is a good conductor of heat, allowing the frying pan to heat up quickly without melting

Question 4

define density

Answer 4

density refers to the amount of matter of an object has compared to its size

Question 5

define mass

Answer 5

mass refers to the amount of matter in an object

Question 6

what is the SI unit of mass?

Answer 6

kg, g

Question 7

what apparatus are used to measure mass?

Answer 7

using electric balance

Question 8

define volume

Answer 8

volume refers to the amount of space an object has

Question 9

what is the SI unit of volume?

Answer 9

m³

Question 10

apparatus used to measure volume?

Answer 10

using measuring cylinder, beaker, pipette, burette
syringe (mostly for gas)

Question 11

how to measure length?

Answer 11

measuring tape (for longer lengths and curved surface)
digital calipers (for short lengths and diameters of small objects)

Question 12

what is SI unit for length

Answer 12

metres (m)

Question 13

convert 10m into cm³

Answer 13

10cm³

Question 14

convert 1L into cm³

Answer 14

1,000cm³

Question 15

convert 1m³ into cm³

Answer 15

1,000,000cm³

Question 16

convert 10cm into mm

Answer 16

100mm

Question 17

convert 1m into cm

Answer 17

100cm

Question 18

convert 1km into cm

Answer 18

100,000cm

Question 19

convert 1km into m

Answer 19

1,000m

Question 20

steps involved in carrying out a scientific method

Answer 20

make an observation -> ask questions -> construct hypothesis -> carry out experiment -> analyse results -> make conclusion

Question 21

difference between independent and dependent variables

Answer 21

independent: variables that can be changed (different in each test)
dependent: variables that cannot be changed (observed and measured in each test) eg. height of plant

Question 22

why is it important to close the air-hole fully before lighting a Bunsen burner?

Answer 22

to prevent a strike-back

Question 23

what flame is obtained when the air-hole is closed?

Answer 23

Luminous flame

Question 24

which flame is more visible to the eyes

Answer 24

Luminous flame

Question 25

which flame should be used for heating? explain your answer.

Answer 25

non-luminous flame. it is hotter and steadier than luminous flame

Question 26

if the Bunsen burner was to be left unattended for a short while, which flame should be used and why?

Answer 26

luminous flame as it is brighter and easier to see than the non-luminous flame

Question 27

formula of density (draw the pyramid)

Answer 27

density = mass/volume

Question 28

volume of a cuboid

Answer 28

length x width x height

Question 29

volume of cylinder

Answer 29

π r² h

Question 30

volume of sphere

Answer 30

(4/3)πr3

Question 31

why does an object float?

Answer 31

the object has less density than the medium

Question 32

does an object sink/float when it has a higher density than the medium?

Answer 32

the objects sinks in the medium

Question 33

a parallex error can occur when using a ...? (can choose more than one answer)

Answer 33

a. digital calipers b. measuring cylinder c. half-metre rule d. measuring tape

Question 34

apparatus used to measure gas

Answer 34

gas syringe

Question 35

unit for density

Answer 35

g/cm3

Question 36

what is the function barrel of a Bunsen burner

Answer 36

to raise the flame to a suitable height for heating

Question 37

funtion of the jet of the Bunsen burner

Answer 37

to allow gas to enter the burner

Question 38

function of base of the Bunsen burner

Answer 38

to support the burner

Question 39

function of collar of a Bunsen burner

Answer 39

to open or close the air-hole

Question 40

function of air-hole of the Bunsen burner

Answer 40

to allow air to enter the hole

Question 41

function of gas tap

Answer 41

to control the amount of gas entering the barrel

Question 42

which flame is used for heating in the lab? explain your answer

Answer 42

non-luminous flame as it is hotter than the luminous flame and it does not produce soot

Question 43

how to light a Bunsen burner?

Answer 43

Connect the rubber tubing to the gas tap. Turn the collar to close the air-hole. Turn on the collar then click on the gas tap. Adjust the flame by turning the collar.