# The Particle Model 3

Year 10 Topic 1: The Particle Model.
12 Learning Opportunities from Monday the 30th of March until Friday the 8th of May.

Learning Episode 3: Density.
This Learning opportunity has 5 tasks to do.
Target Time: 60 minutes.

Which object weighs more? 100 tonnes of feathers or a 100 tonnes of bricks?

Why might you think that the 100 tonnes of bricks weighs the most?

Task 2: copy and complete sentences using information.
Copy these sentences and then fill the gaps, using the information below to help you.
Density: is a __________ of how ________ something is for its size.
Different materials have different __________.
To calculate density you need to know the __________ and _________ .
Missing words: Volume, Measure, mass, densities, heavy.

Information:
In science, if something is very dense it has a large mass for its volume.
In science, if something is not very dense it has a small mass for its volume.
To calculate the density of something, you need to know: its mass in kg;
its volume in m3 (length x width x depth).

Read the example below, then try the questions.
Information
You need to remember this equation and be able to use it so lets practice.
density = mass / volume
Demonstration question:
A block of aluminium has a mass of 5.4 Kg and a volume of 2 m3.
Calculate the density in Kg/m3
density = 5.4 / 2
= 2.7 Kg/m3
Now try these:

Task 4: Sort some facts and write them down. Analyse a graph.
Write a list of the five most important facts from the text below.
Put the most important at the top.
Information:

When a liquid changes into a gas, what happens to its density?
The answer is that when a liquid changes into a gas, the spacing between the particles increases.
This also means that the volume will increase too!
As a result, the density of a substance decreases when it changes from a liquid to a gas because … mass / volume = density.
Look at this graph and then answer the questions below.

Questions:
1) Describe the trend shown in the graph.
2) Explain what it is showing about how the density changes when ice changes state (ice, water, steam)

Task 2: Density is a measure of how heavy something is for its size. Different materials have different densities. To calculate density you need to know the mass and the volume.