Science Buddies: "Ask an Expert"

Hello my name is Disha and I am a 5th grader. My science fair subject is which type of water is the hardest? What do I need in order to do this project? Please give me some advice Thank you.

Hi Dishapatel,

This sounds like an interesting project! One simple approach would be to collect water from different sources, put equal amounts of water into identical containers, let all of the water evaporate, and compare the residues left behind in the containers. The residues that are left behind will be minerals were originally dissolved in the water and then crystallized when the water evaporated. The harder the water, the more residue should be left behind when the water evaporates.

This would only work if the water you started with does not have sediment or other debris in it. You could compare tap water, bottled water, and distilled water, for example. Distilled water would be a good control because distilled water has been processed to remove dissolved minerals from it.

Post back as you have other questions!

Thank u for helping! I have to write my bibliography in correct formant can u help me on that please.

Hi Dishapatel,

I'm not sure what format your teacher would like your bibliography to be in. The MLA style and APA style are both very common. So, if your teacher hasn't given you a specific format, then I would suggest using one of these two styles. You can see examples of references written in these formats here:

https://www.sciencebuddies.org/science- ... ples.shtml
https://www.sciencebuddies.org/science- ... ples.shtml

You can also check out the guidelines on the "Bibliography" page of the Science Buddies Project Guide:

https://www.sciencebuddies.org/science- ... ml#keyinfo

Post back as you have other questions!

Thank U!