Practical — Determination of the density of different substances
Name:____________________
Date due: _________
Grade:8 ____
Members in group:____________________________________________
Learning outcome: Scientific Investigation
Assessment standards: Conducting investigations and collecting data
Evaluating data and communicating findings
You are provided with blocks of different sizes and volumes. You will be
divided into groups and each group will work on different experiments. Please
use your time wisely since you will be assessed on time management, group
work, cooperation etc. Please see attached rubric for further details.
Follow the instructions and Answer the questions that are on your information
sheet.
Apparatus:
1.
2.
3.
4.
Blocks of different sizes and densities
Different types of scales
Containers with different substances
Rulers, pencils and paper (your own)
Method:
1.
Complete the table by doing accurate measurement and calculations:
 Measure the length, breadth and height of each block accurately in
centimeters (cm) (Remember to avoid the error of parallax)
 Calculate the volume of each block, using the formula V = l x b x h.
 Measure the mass in grams of each block on the provided scale
 Fill your data in on the table.
Material
Wood
Foam
Length
5 cm
Breadth
3 cm
Height
3,6 cm
Volume cm3
54
Mass (g)
28.16
6 cm
1,3
1,8
14,04
0.41 – 0.43
4,5 cm
2,5 cm
3,8 cm
42,75
1.47 – 2
7,5 cm
5 cm
4,9 cm
183,75
600 – 650 -
Polystyrene
Aluminium
(12)
2. Containers with different substances
Pick up each cup up and compare how heavy each one is. Sort the materials
in the cups from least to most dense.
Most Dense
Lentils
Least Dense
Foam balls
Beans
Sand
(4)
3. Compare densities of liquids
Pour some water into a beaker. Add 1 or 2 drops of food coloring to the water
to make it easier to see
Pour a small amount of oil slowly into the beaker – allow the oil to run slowly
down the inside of the beaker.
Experimental Technique:
Messy
(1)
Satisfactory
(2)
Good
(3)
Excellent
(4)
(4)
Answer the following questions on a separate piece of paper:
Experiment 1:
 Calculate the densities for each of the blocks.
(12)
Experiment 2
 Draw a conclusion to the results you got.
(2)
 Explain how this investigation was a fair test. Which variables were kept the
same? Which variable was changed
(3)
Experiment 3
 Use the particle model of matter to explain your results.
Criteria
0
1
(2)
2
3
TOTAL
Organisation
Use of time
Participation
in group
Neatness
Dogs breakfast
Nearly illegible
Sloppy
Neat
12
50
Late handing in will cost you 5 marks per day. If you lose your practical notes, this
will cost you 10 marks
EXPERIMENT 1
ANSWERS
Wood:
D=


=
0.51-0.52
(4)
Foam:
D=


=
0.029 – 0.032
(4)
Polystyrene: D =


=
0.034 – 0,047
(4)
Iron:


=
3,26 
(4)
D=
EXPERIMENT 2
ANSWERS
Since the volume was kept the same the mass influenced the density. The heavier the
container was the more its density. The closer the particles are to each other the denser the
object will be 
(2)
EXPERIMENT 3
ANSWERS
Oil is more dense than water i.e. the particles of oil is closer to each other than
the particles in water therefore the oil will float on the water 
(2)
This was a fair test because the volume of the substances and the containers were kept the
same. The only thing that was changed was the substance itself.