1. Done by: Bryan Ong

2. When we put ice into water, itdoes not sink to thebottom, instead, it stays afloat. Why? 3. When does a substance float?A substance floats if it is less dense,than the other components it is in.The coconut is less dense than sea water,therefore it floats.The capsicum on the other hand, ismore dense than water, thus it sinks. 4. Density? What is Density ?Density is the ratio between the weight ofthe substance to the volume on hand. It isoften noted as grams per cubiccentimeter.Density = Weight / Volume All materials are made up of molecules.These molecules are either tightly packedtogether or loosely bound. The tighter the molecules are packed, thegreater density the object has. Most materials are most dense in theirsolid (frozen) state than in their liquid state. Water is an exception. 5. Then..Why is water an exception ?Most liquids get smaller when they freeze, whichmeans the solid form is denser.Water behaves similarly until it reaches 4oC. At 4oC,water molecules are packed as tight as possible. Thedensity of water is at its maximum. 6. Anomalous Expansion of WaterHowever, when the temperature drops further andwater starts to freeze, its molecules begin repellingone another and start moving apart.Once frozen at 0 degrees Celsius, the water moleculesform a type of structure that has a lot of air gaps. Ittakes up more space but still weighs the same, thusmaking the ice much less dense than liquid water.And that explains why whenwe put ice into water, it doesnot sink to the bottom,instead, it stays afloat. 7. What happens if we ice into:Oil Float in the middleTap Water Float on surfaceSalt WaterFloat on surfaceOil and Tap Water Float on surface 8. OilSalt water Tap water Oil and water 9. Ice forms a layer on the top of the lake or pondactually serves as insulation to protect livingcreatures such as fish and other water animals fromfreezing.If ice were to sink to the bottom, the entire lake orpond would eventually freeze over except for a thinlayer of water that forms during the summer. Lifewould not be able to exist the same way as it doestoday. 10. In Tap WaterWhen the coloured water dropletsbegin to coalesce with the water, thecoloured water can be seen to sink asit mixes, because of its greaterdensity. Tap WaterIn Salt WaterThe coloured water from the meltedice stays on top because of it is lessdense than the salt water.Salt Water 11. In Oil and Oil/Water First, you will see a water droplet hanging from the bottom of the icecube. As the water droplet grows, the ice cube will float lower, as it is beingweighted down by the denser water. Finally, the water droplet gets large enough to pull free of the ice andit slowly sinks to the bottom of the glass. A layer of water accumulatesbelow the oil. In the Oil and Water , the water droplet sinks and begin to coalescewith the water. 12. Ice in Oil Ice in Oil and Water 13. Sourcesttp://www.abc.net.au/science/surfingscientist/pdf/lesson_plan05.pdfhttp://www.worsleyschool.net/science/files/saltandfreezing/ofwater.htmlhttp://pitara.com/discover/5wh/online.asp?story=170Google images