I am doing a science fair. Which of these ideas do you think is best?

Question

Hi!

I am going to do a science fair project on either:

Can plants grow without soil?

Does the amount of Co2 increase when you exercise?

What makes Ice melt fastest pepper, salt, sugar, sand?

which one do you think would make me win the science fair and get really good marks? I am in grade seven!

Thanks!

:)

Answer 1

First, let's answer the questions.

Some plants that live in jungles grow without soil.

The amount of carbon dioxide that you exhale does increase with exercise.

Both salt and sugar will make ice melt faster by lowering its melting point.  Of these two, the one with the highest molar concentration will depress the freezing point the most.  This depends on how you conduct the experiment.

For your experiment, I would suggest the one about carbon dioxide if you can actually measure it as a function of exercise.

Answer 2

i think the CO2 one will be the best- it sounds semi impressive for someone your age and its easy to do...

get a sample group (the people you are going to experiment on) of at least 10 people.

Limewater reacts with CO2- it turns cloudy

the more CO2 there is, the cloudier it will become

so get your sample group to breathe into one test tube with about an inch of limewater in it each (1 test tube per person)

take a picture of the result

get them to skip with a skipping rope for 3 or so minutes, then get them to breathe into a different test tube with limewater

take a picture of result again and then compare picture

Hope this helps....i did a project on this exact topic earlier in the year...believe me, it's a lot harder than it sounds!

Answer 3

Well, if you can make it into a real project, I think that plants growing without soil would be a good choice for someone your age, and it shouldn't be too difficult either.  The Co2 exhaled one would definately be harder, but probably a better end result if you could make it work.