why does ice float on water ? (answer for 9th class boy)?

Answer 1

its because the chemical bonds between the H2O molecules are forced into being longer, expanding the water and forming a crystal (ice). When something at constant mass increases in volume, its density decreases. Thus, ice is less dense than water, causing it to float.

Answer 2

generally a material floats on a liquid surface if it's density is less than that of the liquid surface.
All compounds in solid state are more dense than that in the liquid state, but water is different this behavior makes water unique.i.e. when water is the form of ice it has a density of less than 1000kg/m^3( which is the density of pure water)...
This unique property of water is what makes ice float on water. And any substance with a density less than 1000 should float on water... Then how come we human beings don't float on water(our density is less than 1000) ??may be put it as a different question I will answer to that

Answer 3

Ice floats on water because it has a lower density than water.

Normally, when an object is cooled, it will contract. Hence, its volume decreases and becomes denser.

When water is cooled, it also contracts. But when water is cooled below 4 degree celcius, it starts to expand instead. Thus, the cooled water is less dense. Ice, being at zero degree celcius, is less dense than water. Therefore, ice floats on water.

Answer 4

Why Does Ice Float

Answer 5

Normally if you cool a liquid it becomes dense. Same thing happens to water till 4 degrees Celsius. Further cooling below 4 degree Celsius causes water to expand. Water freezes to form ice at 0 degree Celsius, and expands further.

Due to low density of ice compared to the density of water, the ice floats on water.

Due to this nature of water, i.e. it is densest at 4 degrees, the 4 degree water goes to the bottom of lakes. Only the surface gets too cold and freezes. Ice is also a bad conductor of heat, this slows down the freezing of lower layers. This way marine life in water, can remain in water, although the surface freezes to form ice

Answer 6

Ice floats on water because it's less dense. Also because water, takes up more space then ice so is heavier and will sink while the way ice is makes it lighter!

I wont go into the chemistry of it!

Answer 7

Water is different. With most everything on Earth except freshwater, the colder it gets, the more dense it becomes. Take alcohol for instance. If we were to fill up a 1 liter container with pure alcohol at 30 degrees Celsius (86 Fahrenheit) and then take another 1 liter container and fill it with pure alcohol at 10 degrees Celsius (50 Fahrenheit) the cooler container of alcohol would weigh more. This is because the cooler alcohol is more dense, so more alcohol molecules can fit in the same container. This is true with freshwater too, up to a point. But at about 4 degrees Celsius (40 Fahrenheit) water reaches its densest point. Amazingly, as water cools further, it actually becomes less dense.

Each water molecule is made of 2 hydrogen atoms and 1 oxygen atom. These are connected to one another by very strong chemical bonds called covalent bonds. Water molecules are connected to each other by much weaker chemical bonds called hydrogen bonds between the positively charged hydrogen atoms, and one negatively charged oxygen atom in a neighboring water molecule.

As water gets colder than 4 degrees Celsius (40 Fahrenheit) the hydrogen bonds connecting different water molecules adjust to keep the negatively charged oxygen atoms apart. This results in a crystal latice which begins to form at less than 4 degrees Celsius. This crystal latice is completely formed at freezing, and is commonly known as ice.

So, why does ice float? Like most things that float, ice floats because it is less dense than liquid water. Ice is about 9% less dense. When ice forms, it takes up about 9% more space than it did as a liquid. Thus, a 1 liter container of ice weighs less than a 1 liter container of liquid water, and the lighter material floats to the top. As we said, water is different.

Answer 8

When water freeze it becomes ice. Ice has cage like structure which is formed from Hydrogen and Oxygen bonding . This spaces makes increase in volume of ice . And we know volume is inversily proposition to density. So density of ice is less than water hence ice floats in water.

Answer 9

Like sugar granules, water can make crystals when it becomes a solid. When the water makes a crystal. The water molecules line up in an orderly fashion. The water takes up more space when the molecules are lined up. This makes solid water less dense so it floats in liquid water which is more dense.

Answer 10

because ice expands when it freezes it is less dense than water, do the part that expands will stick out of the water, because when the ice floats is will displace its weight in water, but the extra VOLUME will bob above the water. Hope that is clear.