Hello, scientists.

My name is Mr. Wilshire and in this lesson we're going to be looking at temperature and evaporation.

This is the do and review stage.

The outcome for this lesson is, "I can investigate how temperature affects the rate of evaporation." As always, there are some keywords to consider as we work our way through this lesson.

The first is evaporation.

Next, temperature.

After that, variables.

And finally, conclusion.

Don't worry if you're not too sure what some of these words mean.

The definitions have appeared on the screen for you now, so you can pause the video, have a recap, and restart when you're ready to move on.

First part of this lesson is called investigating evaporation.

Sam and Jacob have been learning all about evaporation.

I wonder if you know what evaporation is.

Pause the video here and discuss, restart when you've done that.

Can you remember what evaporation is? What did you discuss? Can you remember it from previous lessons? Well, evaporation is a change of state from a liquid to a gas.

There you can see a image of a cup of water with an arrow showing how it's changing to a gas.

Evaporation of a liquid can take place at any temperature.

Sam and Jacob have made a plan to investigate evaporation.

They know that temperature affects evaporation, but they'd like to make some measurements to demonstrate this.

Scientists also do this.

They make careful observations, and measurements using a range of equipment.

There you can see two scientists using different types of equipment there to make some observations.

So what equipment would scientists use to measure temperature? Pause the video here and discuss.

Restart when you've done that.

So what equipment are scientists going to use? Are they going to use all the equipment you can see in the picture there? Let's find out more.

Well, thermometers or temperature sensors attached to data loggers can be used to measure temperature.

You may have seen some of this type of equipment in your school.

The thermometer on the left there uses different chemicals to be able to tell you when they react to the type of temperature that's in the room.

The data logger there is a digital temperature sensor, so that uses different sensors and circuitry to be able to tell you an accurate temperature.

You may have some of this equipment in your school.

A thermometer is more likely to be used in a science experiment when you need to measure the temperature of some water.

A data sensor like this may look very similar with a little metal wand at the end.

That's how you measure the temperature.

This metal wand can be inserted into things like fabric, or even types of meat.

So you may have seen this type of sensor used in a kitchen.

If your data logger or sensors don't look like this in your classroom, don't worry.

I'm sure there's some very similar equipment that you can use.

Both of these pieces of equipment can be used to measure temperature, but you do need to be very sensible when you're using them.

The thermometer is a glass tube with some chemicals inside that react to the temperature in the air.

So if this breaks, you must make sure that you tell an adult.

The data logo or temperature sensor uses different circuitry, and of course, needs some batteries, or might need to be plugged into the mains.

So again, if this breaks, you must make sure you tell an adult, so that they can help you and make sure that it is still safe to use.

Both of these pieces of equipment can get an accurate temperature reading, whether that's taken outside or inside, but they do both need to be used in different ways.

Jacob would like to use a thermometer to measure the temperature of a room.

Do you know how to use a thermometer to measure a temperature? Have a quick discussion about this.

Restart when you've done that.

So what did you discuss? How is he going to be able to use the thermometer? Does he need to balance it on his hand, or wave it around in the air maybe? Hm, well, to use a thermometer, you need to, step one, make sure your eye is level with the height of the liquid in the thermometer.

There you can see an image of an eye looking at the thermometer.

So yes, not looking at it from above like that.

Two, keep the thermometer in the same place while taking the temperature reading.

This is going to make sure that it's nice and fair, isn't it? Also, it's a very good idea not to hold that thermometer in your hand, especially if it's one that uses the chemicals inside the glass tube, because then it's going to measure the temperature of your hand, isn't it? Sam and Jacob have planned to carry out an investigation to answer their inquiry question, "Does the temperature of the room affect the time taken for water to evaporate?" Take a moment now to discuss that question with your partner or someone nearby.

What do you think? Is the temperature in the room going to affect the time taken for water to evaporate? And what is the best way of finding out the answer to this? Have a quick discussion now.

Restart the video when you've done that.

So the children have had a go at planning their experiment ahead of this.

They want to find out if the temperature of the room can affect the time taken for water to evaporate.

Either that or they could also investigate how much light is in a room, and whether that affects the temperature in the room, and how that causes things to evaporate.

By conducting their experiment, they're going to need to plan everything first and come up with a method.

So a step-by-step instruction guide of the things that they're going to need to do.

This is then going to help anybody else who might want to come along and do this experiment in the future, because they can follow each of the steps, and see if they can get the same kind of results.

If they do get the same kind of results, they know that they've conducted it in the same way.

If they get different sets of results, then it might mean that they've changed something along the way.

Remember, to conduct a fair test, you need to make sure that you only change one thing.

So I wonder what it is that the children are going to be changing here, that one thing that they'll change to make sure that it's fair.

Let's have a little look at their plans together.

And while we do so, have a little think about if there is anything that you would change if you're going to be doing this investigation.

So here is their plan.

Step one, they're going to take three identical flannels, and find and record the mass of each.

Step two, they're going to spray 25 cubic centimetres of water onto each one.

Step three, they're going to find, and record their new masses.

Step four, they're gonna put one flannel in a hot room, one in a warm room, and one in a cold room.

Step five, they're going to measure the temperature of each room and add it to the table.

Step six, every hour they're gonna find, and record the mass of each flannel.

And step seven, they're going to continue for four, or five hours and compare the results for each room.

They've also, I've noticed, put their flannel onto a tray there.

That means that they can lift up the tray rather than touch the flannel and possibly cause a different outcome for the investigation.

So the results of an investigation can be recorded in lots of different ways.

Scientists may choose to use a table, a chart, or even a graph depending on the type of data that they have collected, and how it is easiest to understand.

There you can see an image of a table, and that's looking at different types of heart rate.

The chart there is simple bars going up and down, and a graph is measured on graph paper, and it looks like they've used a line graph here to measure height and compare it with age.

So how do you think the children should record their results? Which of these is going to be the best way to do it? Pause the video here and discuss, restart when you've done that.

So which of these is the best way to do it? Well, the children decided to record the results in this table.

That's a very good idea.

I think a chart or a graph might be better to do with the results from this table after the investigation.

So you can see the time going down the left side.

There's the different types of rooms that are in there.

And don't forget they are measuring the temperature of the room so that they know how warm, or how cool each room is.

Let's stop and think.

Scientists make careful observations and measurements.

Match the equipment to the measurement for which each would be used.

Have a think.

What does a thermometer measure? What does a ruler measure? What does a set of scales measure? On the right hand side, you've got the words, length, mass and temperature.

Length, you would measure in centimetres or metres.

Mass, you would measure in kilogrammes or grammes.

And temperature, you'd measure in Celsius.

But some different countries prefer to use Fahrenheit.

So which of the pieces of equipment are going to be useful in each case? How did you get on? Here are some answers.

The thermometer measures temperature, the ruler measures length and the scales measure mass.

Stop and think again.

Which of these are ways that scientists would record the results of an investigation? Are they going to use a table, a conclusion, a chart or a prediction? The correct answer here is a table or a chart.

Here is task A, carry out an investigation to answer the inquiry question, "Does the temperature of the room affect the time taken for water to evaporate?" Now, you may use the children's method that we've seen before, or you may have your own ideas as well.

You then need to record your results in your chosen way.

Remember, you could use a table or a chart, but I think really the table is going to be easiest for you to scribble down all of your notes.

Best of luck with your task.

Restart the video when you're ready to move on.

How did you get on? Well, here you can see some possible answers.

Now, yours might be similar, or they may be different depending on the different types of temperature or the amount of water each flannel had.

So here, as you see the time has gone down on the left hand side, the cool room there ranges from 50, all the way to 25, and the warm room does the same and so does the hot room.

The main difference that I can notice here is how quickly each side goes down.

Have a little look at that table yourself, and see if you can summarise anything from this data as well before you move on.

The last part of this lesson is called Scientists answer questions about evaporation.

These are Sam and Jacob's results.

There you can see they measured the mass of the flannel, and the cool, the warm, and the hot room.

Scientists use data that they've collected to answer questions.

So Sam and Jacob's inquiry question was, "Does the temperature of the room affect the time taken for water to evaporate?" How will they know the time taken for the water to evaporate though? Pause the video here and discuss.

Restart when you've done that.

So how are they going to know the time taken for the water to evaporate? Jacob has the answer here.

"The mass of each flannel depends on how much water it has in it.

The more water, the heavier it will be." "So as the water evaporates." Sam says, "The mass of the flannel should decrease." "Yes." Says Jacob, "And the more water evaporates, the more the mass decreases." The dry mass of the flannels was 25 grammes.

So how long did it take the flannel to reach 25 grammes in each room? They've all managed to get to 25 grammes.

But is there a difference? Have a look at this data and discuss, restart when you've done that.

How did you get on? You may have noticed that in the cool room, it took five hours.

In the warm room, it took three hours, and in the hot room, oh wow, it only took one hour.

So have a good thinking here.

Use the data to answer the original inquiry question.

"Does the temperature of the room affect the time taken for water to evaporate?" What did you think? I think yes, definitely so far, I can see that the temperature of the room is definitely having some sort of effect, isn't it? Jacob agrees.

He says, "Our results show that water evaporated from all of the flannels, but it took less time for the water to evaporate from the flannel in the hot room than from the flannel in the cold room." So although the water can evaporate at low temperatures, evaporation happens more quickly at higher temperatures.

Let's stop and think.

What's the main reason that scientists collect data? Is it to create diagrams, to answer questions, or to spend time in the laboratory? The correct answer here is to answer questions.

That's why scientists collect data.

How does the speed of evaporation change as temperature increases? Is it because evaporation gets quicker as temperature increases? Is it the speed of evaporation is not affected by temperature, or is it evaporation gets slower as temperature increases? The correct answer here is A, evaporation gets quicker as temperature increases.

So here is task B.

You need to use your results here to answer the inquiry question, "Does the temperature of the room affect the time taken for water to evaporate?" Use the results table from before, and have a good think about how you can scientifically answer this question.

Don't forget, you can even use some of the key words in your description too.

Best of luck with that task and restart when you've done that.

How did you get on? Your summary might be similar to this.

It says, "Our results show that the temperature of the room does affect the time taken for water to evaporate." It does.

Water evaporated from all of the flannels, but water evaporated from the flannel in the hot room in less time than in the cold room.

Hopefully you've noticed some of those things as well.

And using your results, you've been able to write a decent description of what happened in the experiment, and remembering what it has told you.

What have you learned from that experience or experiment? Let's summarise our lesson.

Scientists make careful observations, and measurements using a range of equipment.

The results of an investigation can be recorded in different ways.

Scientists use data they have collected to answer questions, and although water can evaporate at low temperatures, evaporation occurs more quickly as the temperature increases.

So by completing that experiment, hopefully you can see how water can evaporate at any temperature.

Maybe you could go forward, and try this with different size puddles in different areas of the school, but make sure that you warn someone that you're doing it first.

I'm your Mr. Wilshire.

Thank you very much for listening.