Imploding can

Today we did a few experiments to explore density. We explored how heat affects density and makes substances expand and retract because of temperature.

We put a small bit of water in an aluminium can. As it boiled it turned the water into a gas state which pushed out the air in the can. When the can was turned upside down in the cold water the gas quickly cooled and condensed back to a liquid pulling in the metal as it did so. A cool experiment! We write a procedure for doing this experiment and then an explanation of what was happening to cause the can to implode. We also watched a video of the same concept on a bigger scale.




We also looked again at how when atoms are heated they 'shake' more violently. We were able to see this in action when we dropped some food colouring into both cold water and hot water. The food colouring spread more quickly through the hot water as the atoms were more active.

Because atoms shake more when heated they need more space to move so they spread out. The more they are heated the more they spread out. They spread out so much that solids can no longer remain as a solid so they turn to a liquid. If you keep heating them they spread out more and the liquid becomes a gas. If you keep heating them then you will get plasma. When you boil water the bubbles that rise are actually the H20 turning into a gas as it is heated. They start at the bottom of the jug because that is closest to the heat.



So we have seen that heat affects density, but we also looked today at how different things have different densities just because of the way they are structured. We looked at how salt water is more dense than fresh water. This gave us lots to think about in terms of things like boats, swimming, survival in deep water, and free diving. Could you dive deeper in fresh water as it is less dense that salt water?

I showed them this photo of me in the dead sea in Israel to help explain differences in water density because of salt content.

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Molecules

Today we explored what a molecule is. This is a video that explains it really well.

 A molecule is two (or more) atoms that join and form a bond. This bond is formed by the atoms sharing their electrons.

Some molecules are quite simple like water which is H20 (2 hydrogen atoms and 1 oxygen atom)

  Some are more complex like table sugar which is C12H22O11.

We discussed how putting different atoms together can be just a mixture. It becomes a molecule when a chemical reaction happens. We looked at the following video to show how hydrogen and oxygen can be combined to make water.

We also looked at this video showing how a molecule can be returned to separate atoms.

The universe's ingredients!

Today we started to look at the periodic table - the ingredient list of all matter. We looked at how each element consists of a different atom. We explored atoms more and learnt that atoms are different from each other because of the number of protons in each one. Every element has a different number of protons (it is written on the table as the atomic number). Some elements have over 100 protons (most atoms also have the same number of electrons as it has protons). Currently there are 118 known elements. There could be more discovered but since they will have so many electrons/protons they will be quite unstable.

We looked at which elements we are familiar with and discussed questions like why steel is not on the table (it is a metal made from a combination of elements).

We discussed how humans have about 40 elements in their bodies but only 4 elements make up most of the  body - oxygen, carbon, hydrogen, and nitrogen.

It was so good to see the students curiously asking so many questions about the teeny tiny atomic level.

Atoms

We started to discuss atoms yesterday - the smallest part of matter. We watched some great videos to help us get our heads around the size of atoms and their structure. We discovered that all matter is made up of atoms. Everything - trees, stones, air, eyeballs! Atoms are also constantly moving, so even a rock is constantly moving. We started to raise the question of how scientists know all about atoms when they are so small. A big question! We discussed how we can't see the wind but we can learn about wind by looking at the effects of the wind and how it affects objects in different situations. It is a bit like that with studying atoms.

The structure of an atom.

Atoms are ridiculously small. The photo on the right is a photo of the shadow of an atom. Scientists directed a laser beam at a suspended atom and this was it's shadow. The first visualization of an atom. We watched the below videos to help us get our head around how small they are and how they are structured. 

We also noted that electricity is when the electrons in atoms flow (swap) between electrons in other atoms.

Is there anything in the box.

Our inquiry this term is on the material world and we started off by looking at whether a box with no object in it is actually empty. Is air something or nothing? We learnt that 'matter' is the world all around us. We can tell if something is matter by whether it, TAKES UP SPACE and WEIGHS SOMETHING. So we tested this with air and found that, yes, it does take up space and it does weigh something. Here is a video of some of the things that helped us learn this. Sophie helped us see that it is impossible to blow up a balloon in a bottle as the air in the bottle has nowhere to go. We shrink wrapped some students to explore how air takes up space and we used some balloons to see if air weighs anything.



 Wonderings: I wonder if there are places with no matter at all? Does air weigh the same when it is polluted? Or hot?

We have also had a great discussion around which of these (below) are matter and which are not. The ones that really got us thinking were smell, electricity, anger, heat, and a shadow. A great discussion for helping us understand what is matter and what is energy.



We are going to explore all sorts of other things about the material world, including zooming into the particle level of atoms and molecules.

Well we finally made it to some snow. After a few mountain postponements we made it to Snow Planet. It was so good to see so many first timers progress through the day to being confident going down the slope. Well done guys for persevering and taking on the challenge. It was also great to see the more experienced ones learning new skills too. Thank you to the parents who helped make the day possible.