Science Fair...

[Rex.]

Any suggestions for simple Experiments? I will have a Science Fair day soon. I need to do an experiment. Anything amazing and simple.

No chemicals, flame, animals.

 

[Dr Super Good]

No clue what a science fair day is. I am guessing it is some sort of USA school thing?

If you are in primary school then doing one of those solubility experiments might be enough. Basically drinking bottles (eg coke, water) that you mix 2 substances in which do not dissolve. One bottle could be cooking oil and water, another water and sand and one for salt or sugar, or possibly even more. No matter how much you shake the oil and water, they will not mix permanently. No matter how much you shake the sand, even if it appears cloudy, it will eventually settle out. Although the salt and sugar will at first settle at the bottom, over time they will disappear and dissolve into the water (unless the water is saturated with stuff already). You could even mix the sand, water and oil into a single bottle and they should still separate!

The same experiment could work at highschool as well. However you will need to go into more detail about the science at work. For example the densities of water, oil and sand applying force to settle at different levels. With the sugar and salt dissolving you could explain the change in energy that occurs, and show that the resulting solution has less volume than its ingredients due to how the packing works. You could show how detergent acts as an emulsifying agent for oil in water so that it allows oil to dissolve in water. Obviously explain everything in detail, and throw out a few examples in real life (eg detergent used to help clean dishes).

If you want a physics one then you could do one of those diffraction grating experiments. Get white light and shine it through very fine uniform grating (might be hard to get?) onto a sheet of white paper. Due to how interference works, you will find that multiple spectrum appear on the paper. Changing the colour of light, eg with a filter will remove certain components from the spectrum.

You can also do one of those audible interference experiments. Basically two speakers far apart producing the same reasonably loud (not too loud, less than 90 dB for safety) low frequency sound wave. As you move your head around you should be able to sense it getting louder and quieter due to interference.

It might help to give us some context to what you are looking for. Eg what level of school you are at.

 

[Rex.]

Igcse secondary school

 

[Archimmonde]

Uranium experiment

 

[Warseeker]

Radioactivity.

 

[Shadow Fury]

Get a big bowl of water. Get a lot of caesium. Mix them. BOOOOOOOM!

Dr Super Good, your ideas are great but the physics ones you said are related to Physics Advanced Subsidiary level (the one I'm currently taking) and, to my knowledge, Rex is still in the Ordinary Levels so he doesn't know about constructive/destructive interference and Young's double slit experiment (he should use monochromatic light to get the desired effect instead of using filters).

My idea for a physics experiment is constructing an a.c generator (physics OL, should be easy for you). I guess you know how it works.
For chemistry, you could try electrolysis of some solutions (e.g aqueous sodium chloride). If not, you could try to make a cell using two diverse metals of different reactivity.
For Biology, there are pretty many things you can do e.g (food tests, testing leaves for starch, factors that affect photosynthesis etc...). Try what you prefer or you find the easiest.

 

[The_Silent]

Potato battery?

 

[Roland]

How about the Magic Burning money? Or the Elephant Toothpaste?

 

[Celaquil]

This isn't SE Roland. Behave.

Anyway, aside from what DSG and Shadow Fury said, these are some pretty cool
science "tricks":

 

[fladdermasken]

 

[Dr Super Good]

Dr Super Good, your ideas are great but the physics ones you said are related to Physics Advanced Subsidiary level (the one I'm currently taking) and, to my knowledge, Rex is still in the Ordinary Levels so he doesn't know about constructive/destructive interference and Young's double slit experiment (he should use monochromatic light to get the desired effect instead of using filters).

They are Scottish Higher Physics experiments (high school year 5). From what I understand he is still in equivalently Scottish Standard Grade (high school year 3 and 4, like British GCSE). Do be aware I did mention them before he told us what level he is at.

Also if he really wanted to impress, doing something like that would since it is above his level. Not like the mathematics involved is even hard, as far as I recall it uses simple trig functions.

 

[Flux]

The Double Slit experiment would be simple to do but I doubt it will attract attention since the result is only stripes of light. But if you plan to do that, maybe take a big basin with you, fill it with water and demonstrate wave interference on the water waves. Then also present the Wave-Particle duality while you're at it and mention how our observation affects the outcome.
Another cool idea for a science fair would be something like a Coilgun or a Hovercraft, or you know the all-time favorite baking soda volcano .