Isabelli (10) asked a follow up question on- Why are things absorbed and how does temperature affect water?

Isabelli, a couple of interrelated interesting questions. I asked my team to prepare the scene …be back later.

adsorption-absorption

First a little experiment. Put a small amount of water into a saucepan and place it on a heat source (parental permission required) carefully observe what happens (observation is an incredibly important science skill). Make notes of what you see. when the water is obviously boiling switch off the heat source and leave the water to cool down. Avoid moving it. Now repeat the experiment, again making notes on your observations. Are there any differences?

Look at the water molecules in the diagrams above. Water is a dipolar liquid. That means that there is an uneven charge distribution in each molecule. It has a negative ‘end’ and a positive ‘end’. This gives it the capability of making the Oxygen molecules (which are not normally dipolar) dipolar and subsequently creates an attractive force between the water and Oxygen molecule (bit like two magnets). The Oxygen molecules like this arrangement and are held within the water structure.

But …. if you heat up the water the water molecules begin to move about faster so the tentative attraction between the water molecule and the oxygen molecule breaks and it escapes from the water. Can this explain what you observed when you heated the water?

Thanks for your comment. Please feel free to ask further questions and make further comments.

Stirling (8) asked – “How is fire hot and how does it burn you?”

fire

Thanks team, yes I agree, it is all about energy. In a question some time ago I tried to give my thoughts on energy. An explanation I like is “Something has energy when it has the capability of doing something to something else.” I then gave some examples of different forms of energy and what they could do to something else. I think I suggested that different forms of energy can be converted into other forms of energy. For example electrical energy can be converted into heat energy.

So where does the heat energy come from in your fire? Think of the fire. What is burning? Where did it come from? What help create this material that is burning? What type of energy started the process of creating the energy that ended up as heat energy.

Here is a list of different types of energy involved. Can you put them in the correct order, heat energy, solar energy, chemical energy, heat energy, chemical energy,

The heat energy burns you by destroying the cells on your skin.

So beware do not experiment with fire on your own. I could be very dangerous. Make sure you have an adult with you.

Clara’s (7) asked “Where do puddles go to?”

Many thanks for the great question Clara. I put it to my friends and as usual they came up with some interesting thoughts.

puddles
Many thanks team.

Excellent thoughts. What we need to do is set up some experiments that might help us find a possible answer. If we had a bowl of water how would we protect it from insects, and other animals drinking from it? How would we prevent leaks into the ground? How would you stop the Sun grabbing it?

This could lead to lots of different experiments so you have to think about how you can make them into a fair test. For example you have a bowl of water, how much water is in it? You leave the bowl on a window ledge for a couple of days – to see the Sun. Can you fairly compare it to a bowl of water in a cupboard , unless you keep some things the same?

How did you protect the bowl on the window ledge, from animals? How much Sun was there?
Wow.

Fair testing is an important part of scientific investigations, it is difficult but amazingly rewarding. Get involved in trying to answer the question and then you are the scientist.

Let us know your thoughts/answers by using the ‘Leave a Reply‘ section below. Unsure about something..then Ask a Question.

Here is a little video of somebody else with the same problem. It uses a word that you might not understand ‘evaporation’. If you want help Ask a Question.

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

Two questions on electrocution and why does my phone get warm?

…. a couple of interesting questions. Which I will answer.

Electrocution is the term used to describe death from an electric current.

If you are going to die from an electric current it has to have certain properties. The voltage (or push) of the current must be high enough and the amperage (strength of the current) must be high enough. The electric current must also travel through the body in such a way that it passes through the heart or brain because it is those two organs that are most easily damaged by electricity (they both operate using electrical signals produced by the body). Electricity also has to have a pathway to the ground so if your feet are covered with an insulating material it might burn you (at point of contact) but is unlikely to kill you. To electrocute you the voltage could be as low as 40 volts and the current 500mA. Remember a battery can only produce a push of 1.5 volts and provide a current of 2000mA so even though the current is high the push is very low.

Mains electricity has a push of 250volts  and can provide a current of 13,000mA so it is very, very dangerous. Never, never, play with mains electricity. 

Warm telephones are caused by your working battery. Your battery is pumping electricity around your phones circuits. That electricity is lighting up the screen, and converting your voice into electrical signals, and converting the electrical signals of the person you are talking to into sound energy and sending the signals. It’s doing a lot of work. You get hot when you are working and try to cool down, the battery gets hot and tries to loose that heat by warming up your phone.

I hope these comments answer your questions.