Mason (7) asks “Why is water wet?”

Thanks team. Let us start with a investigation. Let us look at the way water interacts with different materials.


Let us now look at the properties of water drops. Firstly let me define ‘cohesion’ and ‘adhesion’. The term ‘hesion’ means  … to stick. Cohesion is is the attraction and sticking together of the same things while adhesion is the attraction and sticking together of different things.

Look at the image of the water drop below. Each water particle is attracted to the other water particles around it , this is cohesion. Now add a different surface and the water particles are attracted to that rather than each other, this is adhesion. When adhesion occurs we get the spreading of the water drop and wetting,  providing the adhesive forces are greater than the cohesive forces.

So what about your investigation? Is there any evidence of cohesion or adhesion?

Here is a thought. it has been suggested that water is ‘wet’ because you can feel it’s wetness.

Maybe another little experiment.

You could let me know by clicking on the ‘Reply’ box below.

Laura G (10) asked “Is it possible to collect condensation to water a garden?”

Laura, have you ever on a warm day noticed faint water droppings on leaves of some of your plants. Where has this water come from? It might have come from the leaf itself or alternatively it might have come from the atmosphere. The atmosphere/air around us can hold an immense amount of water in its vapour form. For example a parcel of 1 cubic meter of air at 30 degrees centigrade could contain 28g ( or 28 cc) of water. There is therefore a good chance that those drips on the leaf came from the atmosphere.

The fog fence provides a surface that is colder* than the air around it and therefore a place where water vapour can condense and the water collected. The water can then be used for irrigation of plant life AND the plant life itself generates it’s own water vapour so it is possible to use a fog fence , in a desert like area to collect water, feed it to plants and begin the process of creating a self sustaining green environment.

I am happy for suggested revisions to the above arguments.

*Sorry Laura,I have given you a completely wrong bit of information. It is very unlikely that the fence would be at a different temperature from the air around us. So how does it aid condensation?  It’s made of metal. What do you feel when you touch a metal object that has been lying around on your table?.

See a previous question that may give you a clue.

It feels cold. Why? It should be at the same temperature as the rest of the objects on the table. It feels cold because metal is a good conductor of heat and as your fingers are quite warm it conducts the heat away from them and they feel cold. Maybe the metal in the fence is conducting heat away from the water vapour and because it loses heat it changes from the vapour form to the liquid form …..condensation.

Para added 15/10/17

link added  15/01/18

Indianna (10) asked “If all the ice melts in Antarctica will we all drown?”

I agree. It has been calculated that the sea level would rise by about 260 ft or 70 m. This would mean cities like London and Paris would disappear BUT there still would be a lot of land. We would not all drown however life might be a bit difficult because of the crowding.

If you would like to make a comment on this answer please make it in the Reply box or ask another question. Thanks for the question Indianna.

Kelly (9) asks “Why when we have been in water for too long, does our fingers and other parts of our body become soggy and wrinkly?”

Thanks team, a good start. The water soaks into the dead skin. There is lots of dead skin on our hands and feet. There are parts of our bodies which have very little dead skin so you will find that the wrinkles do not appear there. It was thought that the soaked up water caused the skin to swell and get puffy and the wrinkles were formed.


It is now thought by some that the wrinkling is a nervous reaction to the water attack on the body and that the wrinkled skin is a counter reaction to the skin becoming slippery because of the water intake (wrinkles help you hold things). What do you think?

Maybe you could record your thoughts in the Leave a reply box


“How does sound travel in things other than air?” asks Lilly(12)

Hello Molly, Science Master here. Lets’ check that we understand how sound is produced and what it is. Sound is a form of Energy ( see Science Master Special).  It is transmitted by particles hitting each other.

So what do you think? Could you hear the sound underwater?  Could you hear the sound further along the metal tube?

Lets improve the experiment by making it fairer. How could we do this?

Let us look at the particle arrangement in the air, water and metal.

The average distance between particles for a gas is 4 nanometers (1 nanometer = 10-9 meters), for a liquid it is 0.2 of a nanometer and for the solid 0.0002 of a nanometer.

So. If the first line of particles in the gas starts moving it has to travel 4 nanometers before it hits the second row. For the liquid this would be a smaller distance and for the metal it would be hardly any distance. What does that tell you about the speed of travel of sound?

Does your experiments support your thoughts? Maybe it needs to be modified? How could you modify it to really test your thoughts.

Just a thought of my own. The sound source (drum, spoon tapping, violin) gives the particles around it ENERGY. Those particles in air have to travel a long distance before they hit another particle and pass the sound on. All this time they are losing ENERGY. For the metal the particles only have to travel a little way before passing on the vibration.

(added 27/10/16)

Not sure of something Lilly…ask another question.

(Anyone reading this post who wants to ask a question or make a comment please feel free to do so)

“Why do stars twinkle” asked Mia (8)

Many thank team. I think Mia has all she needs for a little bit of experimentation.

Mia, in a darkened room , put the aluminum foil on the floor, place the bowl over it and shine the torch onto the bottom of the bowl.

What do you see?

Now add some water to the bowl(about half full). Let the water settle and then shine the torch onto the bottom of the bowl.

What do you see?

Finally, still shining the torch onto the bottom of the bowl give the water a bit of a vigorous stir with a spoon or even the end of a pencil.

What do you see?

Is what you see when the water is moving different from when it is not moving? Maybe the moving water is a bit like the moving air through which you are seeing the stars.

Tell us what you see. you can do this in the Reply box below.
(Anyone reading this post who wants to ask a question or make a comment please feel free to do so)

Billie and Zali (10) asked “How does the activator form slime?”

Sorry team.  You have provided some good background material. The important thing about making SLIME is that all the ingredients in it’s making (The Activator, the PVA and water)  have something in common, lots of O-H chemical bonds. It is these that make the SLIME a reality. Look at the diagram of a PVA molecule and count the number of O-H bonds. Remember this is a Polymer so the image below is just one bit of a much bigger molecule of PVA.

So what is it about the O-H bonds that make them so important.

Look at the following short video ….



It’s all due to Hydrogen bonding. Everything is attracted to everything else by the Hydrogen bond environment that is introduced when you put all of the ingredients together. SLIME becomes the reality.

Think about it. Make a comment or if you don’t understand a complicated bit then please- Ask another Question
(Anyone reading this post who wants to ask a question or make a comment please feel free to do so)

(revised 13/9/17 – PVA is polyvinyl acetate not polyvinyl alcohol, Diagram of PVA included and last paragraph revised)

Donna (7) asks “Where do clouds come from?”

Donna, many thanks for the question. Before trying to answer it I thought I would ask my team a question.

Donna, what do you think about the puddles question? Think about how you would answer it and then go to my answer to a previous question.

Now to your question. Firstly I have created a little animation to show how the puddle disappear. You have to imagine that the shapes are water particles (molecules is the proper word). In the puddle they are all moving around. Most of them like being with the other particles BUT some are just moving around a little bit too fast and manage to escape from the puddle. When the Sun begins to warm the puddle it makes more water particles move around faster and more escape. This goes on until the puddle disappears.


The water particles are very small and are are lifted by the air up into the sky. High above the ground the air is quite cold so the water particles ‘slow down’. When they are moving ever so slowly if they meet another water particle they join up with each other and form droplets of water. This is how a cloud begins to form.

At home look at the steam from a kettle, BE VERY CAREFUL AND CONSULT AN ADULT.  At the exit of the kettle spout you can see nothing, BUT just above this the hot water particles begin to cool down and slow down and reform clouds of water.

(revised 21/4/17)

Jamie asked a question – “Why does water sometimes boil at different temperatures?”

I must apoligise to Jamie because he specifically asked about the water in Yellowstone River boiling at 106 0 C.  Why does it do that? Does water boil at a higher or lower temperature in other situations? I asked my friends about this.

Jamie, the properties of water does depend on it’s intermolecular structure. If it didn’t have these intermolecular forces (called hydrogen bonds) the water would likely be a gas at room temperature. Life on Earth would therefore be impossible or maybe very different.

Ok, water is as it is now, so why can it’s boiling point change? The main reason is the environment in which it is trying to boil, not the water. Boiling is linked to the process of the water molecules getting enough energy from the heat source to make it move so fast that the intermolecular forces can be broken and it can escape from the water into it’s environment.


If the environment is changed this can affect the boiling point. Make the environment thicker(more dense) and the water molecules have greater difficulty in escaping making the boiling point go up, in the kitchen a pressure cooker prevents the faster water molecules from escaping.  Make the environment thinner (go up a mountain, where the air is ‘thinner’) and you make it easier for the water molecules to escape so the boiling point goes down.


There is another way to affect the intermolecular forces of the water molecules. Introduce something into the water that increases the intermolecular bonding. Introducing salt NaCl, which gives Na+ and Cl ions in water. These make it more difficult for the water molecules to become gaseous molecules so the boiling point go up.

There are other posts that could help you…..On intermolecular forces and a game you could play and adapt.

Science Master Special – What might plants need to grow?

1. Air (Oxygen and Carbon Dioxide)
2. The Sun or some light or maybe some darkness.
3. Warmth (heat), or maybe some coolness.
4. Water (moisture, dampness)
5. Soil, rocks, compost, sand.
6. Time, lots or maybe little.
7. Creatures, in or above the soil. These could be giant worms or miniscule creatures.
8. Plant food. Fertilisers, minerals.


This list was helped by The Nuffield Space Project P77