Robert Boyle was a famous scientist who lived 350 years ago. He helped create the Royal Society, which started as a group of scientists who would share their scientific ideas and carry out experiments, just like scientists today. But unlike scientists today, who usually study just one subject, he studied all branches of science, from how we breathe to how sound travels.

This page contains information on Robert Boyle's range of interests. Much of his work involved air, what it is was and why it was needed.  Below is a selection of short experiments which help demonstrate some of his discoveries.

 

Air is needed for things to burn.

You will need...

Two small tea lights
One large glass
A heat resistant surface

How long will it take?

This demonstration takes only a few minutes to put together and do.

What to do...

1.  Take two small tea lights and put them on a heat-resistant surface.
2.  Light both candles and put a large glass over the top of one of them. After a short while the tea light under the glass will go out as it uses up the oxygen in the glass. The other tea light will remain alight.

What's happening?

The candle under the glass burns up the oxygen and goes out. You can relate this to a diagram of a Fire Triangle which helps show what fire needs to burn.


Sound needs to travel through something.

You will need...

Cling film
An empty bowl
A handful of cous cous

How long will it take?

This demonstration takes only a few minutes to put together and do.

What to do...

1.  Put cling film over an empty jar or bowl.
2.  Put the cous cous on the cling film and shout at it.
3.  Shout at different pitches (higher or lower notes) and different volumes and watch what happens to the cous cous.

What's happening?

As you shout at the bowl, the air inside vibrates making the cous cous jump around on the top of the cling film. The higher the pitch, the faster the vibrations.

Taking the air out.

Boyle did many of his experiments on air with his assistant Robert Hooke.  They built a machine that could suck all of the air from out of a jar.

You will need...

A lot of marshmallows -  long thin ones are best
An empty wine bottle
A wine bottle vacuum pump and stopper

How long will it take?

This demonstration will take about 15 minutes. 

What to do...

1.  Put some the marshmallows in the bottom of the bottle (you may need to squash them a little to get them in).  Try not to make the inside neck of the bottle too sticky as this can make it very difficult to get the marshmallows in.
2.  Put on the wine stopper and start to pump out the air. Give them a shake every now and then to give them a bit of space. Watch as they grow.
3.  Then, take the stopper out and watch them deflate.
4.  You can also put a balloon in the bottle - push it in while deflated leaving the end poking out the top. Blow it up a little and then tie it. Push it into the bottom of the bottle. Now pump out the air and watch as the balloon inflates.

What's happening?

As you pump the air out of the bottle, you are removing some of the air pressure that was pressing on the marshmallows. When there is less air pressure, the bubbles inside the marshmallows start to push outward and expand. When you let the air back into the bottle, the marshmallows get squashed back to their original shape because of the pressure caused by the air.


Home made indicators

Robert Boyle made indicators: substances that are used to test if something is acidic (like lemon juice) or alkaline (like soap).

You will need...
 
Chopped up red cabbage
Boiling water
10 small beakers, test tubes, or small glasses
Filter paper (coffee filters will do)
Lots of different substances to test like lemon juice, laundry detergent, hand soap, baking soda

How long will it take?

This can take about an hour to do from start to finish, but you can prepare the indicator in advance and just use it to test the different materials.

What to do...

1.  Put the red cabbage in the boiling water. Leave it for about 10 or 15 minutes.
2.  Once done, collect the cabbage water by filtering out the solid cabbage bits.
3.  Pour a little of the cabbage water into each of the small beakers. Add a substance to be tested to each beaker, and watch as the liquid changes colour!

Red = acid (e.g. lemon juice), purple = neutral, blue = alkaline (e.g. baking soda).

What's happening?

Red cabbage contains pigment molecules called anthocyanins. Anthocyanins will change their colour depending on the pH of their environment. Red indicates an acid, purple indicates neutral and blue indicates alkaline. You can ask the students to create a chart of their findings using coloured pencils to shade a coloured square for each substance you are testing.

Water expands as it freezes.

You will need...

Some balloons
Water
A Freezer
Some string

How long will it take?

It is best to leave the balloon over night to freeze, but the preparation takes only a few minutes.

What to do...

1.  Fill balloons with water - a little in the first, more in the second, and even more in a third.
2.  Put the balloon on a table and use a piece of string to measure the circumference (the distance around the middle) of the balloons. Make a note.
3.  Now freeze them all (try to put them in a freezer where they can sit upright). Once frozen take them out and measure them again.

What's happening?

Unlike a lot of liquids, water expands when it freezes because of its structure. As it freezes, the hydrogen and oxygen atoms that make up water bond together leaving gaps in the structure and making it take up more space than it did as a liquid. You can find out by how much water expands by measuring the three balloons before and after freezing.

Curriculum Links  

Science:

Working Scientifically

 

Lower key stage 2 Year 4
States of matter
Sound

 

Upper key stage 2 Year 5
Properties and changes of materials

Numeracy:

Measurement

 

Statistics

History:

A study of an aspect or theme in British history that extends pupils' chronological knowledge beyond 1066

 Scottish Curriculum

Science:

SCN 2-05a

Planet Earth - Processes of the planet

 

SCN 1-11a

Forces, electricity and waves - Vibrations and waves

Collaborating in experiments on different ways of producing sound from vibrations. Demonstrating how to change the pitch of the sound. [Note: level 1)

 

SCN 2-11a

Forces, electricity and waves - Vibrations and waves

Explaining how sound vibrations are carried by waves through air, water and other media.

 

SCN 2-15a

Materials - Properties and uses of substances

 

SCN 2-19a

Materials - Chemical changes

Social Studies:

SOC 2-06a

People, past events and societies

Mathematics:

MNU 2-20b

Information handling - Data and analysis.

Technologies:

TCH 2-01b

Technological developments in society

Robert Boyle carried out many experiments on air. He didn't know that air was a mixture of gases and the one important to us was oxygen, but he worked with air and found out that:

 

Candle

 

1. the body breathes in something from the air;

 

2. air is needed for things to burn;

 

3. sound needs to travel through something;

 

 

 

 

Bioluminescent sea creature

 

 

4. gases could be made of lots of tiny particles, and these move about freely;

 

5. bioluminescence needs air too. Bioluminescence is where some insects such as a glow worm and sea creatures can light themselves up by mixing up two chemicals just like a glow-stick.

 

 

Boyle did these experiments with his assistant Robert Hooke by building a machine that could suck all of the air from out of a jar.

Robert Boyle didn't just study air. He studied how water expands as it freezes and he made indicators: substances that are used to test if something is acidic (like lemon juice) or alkaline (like soap).

Here are a selection of short experiments which will help demonstrate some of his discoveries.

 

Air is needed for things to burn.

You will need...

Two small tea lights
One large glass
A heat resistant surface

How long will it take?

This demonstration takes only a few minutes to put together and do.

What to do...

1.  Take two small tea lights and put them on a heat-resistant surface.
2.  Light both candles and put a large glass over the top of one of them. After a short while the tea light under the glass will go out as it uses up the oxygen in the glass. The other tea light will remain alight.


Sound needs to travel through something.

You will need...

Cling film
An empty bowl
A handful of cous cous

How long will it take?

This demonstration takes only a few minutes to put together and do.

What to do...

1.  Put cling film over an empty jar or bowl.
2.  Put the cous cous on the cling film and shout at it.
3.  Shout at different pitches (higher or lower notes) and different volumes and watch what happens to the cous cous.


Taking the air out.

Boyle did many of his experiments on air with his assistant Robert Hooke.  They built a machine that could suck all of the air from out of a jar.

You will need...

A lot of marshmallows -  long thin ones are best
An empty wine bottle
A wine bottle vacuum pump and stopper

How long will it take?

This demonstration will take about 15 minutes. 

What to do...

1.  Put some the marshmallows in the bottom of the bottle (you may need to squash them a little to get them in).  Try not to make the inside neck of the bottle too sticky as this can make it very difficult to get the marshmallows in.
2.  Put on the wine stopper and start to pump out the air. Give them a shake every now and then to give them a bit of space. Watch as they grow.
3.  Then, take the stopper out and watch them deflate.
4.  You can also put a balloon in the bottle - push it in while deflated leaving the end poking out the top. Blow it up a little and then tie it. Push it into the bottom of the bottle. Now pump out the air and watch as the balloon inflates.


Home made indicators

Robert Boyle made indicators: substances that are used to test if something is acidic (like lemon juice) or alkaline (like soap).

You will need...
 
Chopped up red cabbage
Boiling water
10 small beakers, test tubes, or small glasses
Filter paper (coffee filters will do)
Lots of different substances to test like lemon juice, laundry detergent, hand soap, baking soda

How long will it take?

This can take about an hour to do from start to finish, but you can prepare the indicator in advance and just use it to test the different materials.

What to do...

1.  Put the red cabbage in the boiling water. Leave it for about 10 or 15 minutes.
2.  Once done, collect the cabbage water by filtering out the solid cabbage bits.
3.  Pour a little of the cabbage water into each of the small beakers. Add a substance to be tested to each beaker, and watch as the liquid changes colour!

Red = acid (e.g. lemon juice), purple = neutral, blue = alkaline (e.g. baking soda).

Cabbage indicator diagram


Water expands as it freezes.

You will need...

Some balloons
Water
A Freezer
Some string

How long will it take?

It is best to leave the balloon over night to freeze, but the preparation takes only a few minutes.

What to do...

1.  Fill balloons with water - a little in the first, more in the second, and even more in a third.
2.  Put the balloon on a table and use a piece of string to measure the circumference (the distance around the middle) of the balloons. Make a note.
3.  Now freeze them all (try to put them in a freezer where they can sit upright). Once frozen take them out and measure them again.