Amasidda (?) asked “Give one reason to prove that light is form of energy”

 

Then Amasidda you might be able to answer the question yourself.  Think about what all forms of energy – electric (electricity), light, heat (thermal), movement (kinetic), nuclear, chemical, sound, gravitational, can do. Can they all in some way do work? Can they all be converted from one from one form of energy to another?

What do you think ‘work’ is? Let me know in the comment box below.

Keith (13) asked a question about thermal papers in cash machines.

Keith’s question
More and more places are using thermal paper as a form of receipt paper for customers. With time the information fades. How can one scientifically go about recovering information which may have faded from thermal paper.

Keith, many thanks for the question. I never realised that thermal(heat sensitive) paper was used in so many places and that it is also the basis on which the polaroid camera worked.

Thermal paper is made using a collection of dyes which exist as colourless crystals that become coloured when they interact with an acid.


For those who enjoy their chemistry you might have come across adding a dye called phenolphthalein to an acid solution. The dye changes from colourless to a deep purple.

The applied heat (from the cash register machine) melts a layer in the paper which contains acid crystals. The liquid acid then interacts with the layer below it which contains a colourless crystalline dye which changes colour as the acid interacts with it.  The print then shows. The acid quickly becomes crystalline again.

Over time the print does begin to disappear.

A little investigation.

Obtain an old till receipt which your adults do not want to save. Put it onto an ironing board and with a hot (care) iron, iron it.

Stop

To make it more scientific predict what you think might happen before you carry out the experiment. Any ideas, if so you have a hypothesis.  Now find a very old (fading) receipt and using a hair drier blow warm air onto the BACK of the receipt. Again predict.

I think I’ll stop there. Many thanks for the question Keith. Please comment or ask another question.

Lexi (9) and Jaeda (9) and Cadence(8) asked a question on “Minerals”

Lexi, a nice question, a lot of elements are found within the form of a mineral. I shall let my team introduce the answer to this question.

Jaeda. You asked a question on crystals and why are they so expensive. This is not  a science question however most crystals are minerals so this question is also addressed to you.

Cadence . You asked about talc, which is a mineral.

All minerals are found in rocks. It is thought that some are created by the magma (lava) from volcanoes while other were formed in the Earth’s mantle and have reached the surface through earthquake activity. The minerals created from volcanoes have smaller crystals (probably cooled faster), minerals created more slowly in the mantle consist of bigger crystals. All of the minerals are created by a chemical reaction.

A lot of minerals are mined, dug from underground shafts. A lot of minerals have the elements Silicon and  Oxygen in them.Talc is a mineral of the elements Magnesium, Silicon and Oxygen and is mainly found in Japan and the United States.

Have fun and watch this video on minerals.

Thank you Lexi, Jaeda and Cadence. If you want to comment on this post please feel free to do so in the Reply box below. Or why not ask another question.

“When you shake a fizzy drink that is full when you open it and it explodes?” asked Ruby (8)

When you open the bottle you should hear a gentle fizz. When you pour the drink into a glass you get a bigger fizz and lots of bubbles. If you had ice in the glass you would get even more bubbles. This is because the surface of the glass and the ice cubes are full of little gullies and points. The gas bubbles that were hidden in the liquid attach themselves to the gullies and start to get bigger, (bubbles grow by being joined by other bubbles) and bigger and then when they are big enough, because they are lighter than the liquid, they rise to the surface.

Here is a little experiment for you to try —put the ice cube in your mouth and get your tongue to smooth it, for a few minutes. Think about what I have said and try and predict what the outcome will be when you pour a new bottle of drink over it. Now add the carbonated drink and test your prediction.

Now what happens if you shake the bottle before opening it. This is where you get the explosion!  Here is my possible explanation……. look at the bottle of drink.

(1) There is an empty space at the top of the bottle. It’s not empty, it is full of Carbon Dioxide gas.

(2) When you shake the bottle that gas mixes with the liquid and because bubbles attract other bubbles the gas in the liquid becomes more bubbly.

(3) The bubbles that were hidden in the liquid join the new shaken bubbles. Undo the top and these new bigger bubbles all escape at the same time pushing the liquid before it – the  explosion.

Look at this previous post.

 

Ruby (8) asked “What type of chemical is in capsicum that hurts when police put it in eyes?”

Yes, a great question Ruby. There is this temptation to relate Capsaicin to Black Pepper, however this is not true. The black pepper seeds are from a plant in the vine family of plants. The Capsicum family is the home of the chillies and the chemical Capsaicin which is a chemical in the alkaloid family. Capsaicin is not only used in pepper sprays it also has some curative properties, for example it is an effective pain killer.

I think it is very interesting that certain chemicals, particularly those derived from plants can be used for destructive purposes and for curing purposes. Just a thought.

Sadie (8) asked “How do batteries work?”

Sadie, many thanks for your question. I asked my friends to help me…

 

Yes I remember doing that, it wasn’t easy but I did get the led to light up.

Let’s start with a possible definition of a battery – It’s a device that converts chemical energy into electrical energy. If you are uncertain about what I mean by energy then have a look at this site.  

Now why do we have two different metals? Inside the squeezed lemon is a lot of lemon juice. There is a chemical reaction between the metals and the lemon juice. Because the metals are different they react with the lemon juice in different ways. The different reactions give the copper nail a positive charge and the iron nail a negative charge.

Connecting the two nails together with a wire will give you a flow of electrons in the wire from the iron nail to the copper nail. This will continue until the chemical reaction inside the lemon reaches completion.

Your normal battery is like the lemon but obviously made of different materials. Look at the diagram below.

Sadie, I hope you have found this useful. If you or any other reader would like to make a comment please fill in the Leave a Reply box below. And if you are uncertain about bits of the explanation please ask another question.

Additional note …copper nails are difficult to get hold of so why not use a small piece of copper tubing. Also there is a small possibility that a battery was produced over 2500 years ago, see The Baghdad Battery. Ask your teacher about it. Or ask another question.

Luie(12) asks ” What is the most deadly gas?”

Luie I asked my friends for help on this question. They had some interesting thoughts.

posinous gases

Luie, it is not quite true that there is only one gas that is not poisonous. Air consists of a variety of gases that are not poisonous, we breathe them in all the time and they don’t poison us. There is however one gas that is used by our body and is more important than the others. What is it? If you know then you could tell me by using the ‘Leave a Reply’ box

Did you know that Hydrogen Sulphide (bad eggs) is more poisonous than Hydrogen Cyanide (almond smell), why ???

Because our nose is much more sensitive to Hydrogen Sulphide than Hydrogen Cyanide. By the time you can smell the almond smell you are dying.

How is smoke made in a fire? – is a question from Tate (8)

smoke

Tate Please look at Chemical and Heat Energy. It might help explain some of the terms above.

What happens in a fire is that the chemicals (in the wood or coal structure) begin to break up. This gives the fire more energy and the break up gets worse. The initial particles break up into their parts (atoms) and then some combine with the oxygen in the air and give of more energy and form a fantastic gas called Carbon Dioxide which trees breathe.(another story). BUT some don’t get that far and become your smoke (maybe more oxygen was needed). IF your adult could put a cold spoon in the flame of a candle you would see an example of the smoke of a candle.

Never ever play with fire yourself it is very, very dangerous.