Home > Physics > Solids, Liquids and Gases: Ice, Water and Steam

Solids, Liquids and Gases: Ice, Water and Steam

By: Suzanne Elvidge BSc (hons), MSc - Updated: 19 Feb 2018 |
 
Solid Liquid Gas Sublime Water Ice Steam

Water exists in three states – solid ice, liquid water and gaseous steam. Solids have a fixed shape and size. Liquids can change in shape, but have a fixed size. Gases can change shape and size.

Ice

Water freezes at 0 degrees Centigrade and becomes ice. On a cold, dry, clear morning, have a close look at the frost outside – these are crystals of ice.

Most solids are crystalline, where the molecules are tightly bound to each other, and are arranged in specific repeating patterns.

Half fill a clear plastic tub with water and mark the level of the water. Put it in the freezer overnight – does the ice take up more or less room than the water? Drop the ice into a bowl of water – does it float or sink?

In crystalline structures, the solid form of a substance usually takes up less space than the liquid form, because the molecules are tidily arranged. However, water and ice are unusual because ice takes up more room than water. This makes it less dense than water, so it floats (see ‘Floating and Sinking: Looking at Density’).

Water

In liquids, the molecules are connected loosely to each other. This makes water flow and pour. The water molecules at the surface link more strongly to each other, creating what is called surface tension (see ‘Surface Tension: Keeping Bubbles Round and Insects Up’. This keeps water together in drops.

Run a tap slowly, or pour water from a jug into a bowl in a very thin stream and watch how the water molecules stay together and form drops.

Steam

At sea level, water forms steam it its boiling point, 100 degrees Centigrade. Steam is the gas form of water, and is also known as ‘water vapour’.

Put water in a pan and carefully heat it on the hob. Watch the bubbles form and the steam rise from the surface (be very careful – boiling water and steam can burn). Does the steam take up the same amount of space as the water?

In gases, the molecules are not connected to each other and can move around freely. The bubbles in boiling water are bubbles of steam that from at the bottom and rise to the surface. The air pressure in the room stops the bubbles escaping until they reach a certain size. At high altitudes, for example on top of mountains, water boils at a lower temperature than 100 degrees Centigrade because the air pressure is lower, and the bubbles of steam can escape more easily.

Burning Candles

Another example of solids, liquids and gases is a burning candle. Carefully light a candle and watch the surface of the candle and the flame. The flame melts the solid wax, creating a pool of liquid wax. This creeps up the wick inside the flame and becomes a gas, which then burns in the flame. The flame melts more wax and the cycle continues.

Sublimation

A few compounds go from solid to gas without becoming liquid in between. Solid carbon dioxide (dry ice) becomes carbon dioxide gas without becoming a liquid, as does iodine.

In some circumstances, snow and ice can sublime – sometimes, wet washing hung outside freezes solid and then dries without melting. This is called freeze-drying and is used in food preserving and for making instant foods and drinks.

You might also like...
Share Your Story, Join the Discussion or Seek Advice..
I want to ask that why steam and ice are similar? A..they can be compressed B..they can take the shape of any container C..they consists of the same type of particles D..The particles of both has the same amount of energy
Ada - 25-Apr-16 @ 12:48 PM
I was very confused and was not able to find my answer but these answers helped me a lot
dee - 10-Apr-15 @ 10:43 AM
showthe melting point of ice on the graph.
Talco - 30-Aug-12 @ 2:19 AM
Share Your Story, Join the Discussion or Seek Advice...
Title:
(never shown)
Firstname:
(never shown)
Surname:
(never shown)
Email:
(never shown)
Nickname:
(shown)
Comment:
Validate:
Enter word:
Topics
Latest Comments
  • Rea
    Re: Making an Emulsion
    I have always wondered about the Earth. My teacher gave us this website to read about why water and oil don't mix. I started looking around on…
    16 May 2019
  • Candytashy
    Re: Looking at Soil Profiles
    Thanks so much for this post .it really helped me .made my homework much easier and l have learnt a lot from this post
    25 March 2019
  • Rajput
    Re: Pulling and Pushing: Magnetic Attraction
    Kya kisi chemical ko copper me mix karne se iron or steel ko push kiya ja sakte hai. Yadi ho to formula batye.
    25 March 2019
  • AT LIFE
    Re: Soap and Detergent Chemistry
    Thanks you so much because you help different students especially science who went be a perfect a part of chemistry
    22 March 2019
  • AT LIFE
    Re: Soap and Detergent Chemistry
    Thanks you so much because you help d/f students especially science who went be a perfect a part of chemistry like me.
    22 March 2019
  • Ban
    Re: Pulling and Pushing: Magnetic Attraction
    Sir, I found that in magnet the needle attract one side and repulsive other side pls give me the answer
    6 March 2019
  • falcon
    Re: Growing Plants in Different Soils
    this has been very helpful for my science experiment thank you
    19 February 2019
  • Suzwriter
    Re: A Bending Bone
    The bones soaked in water won't change - it's the acid that affects the bones. And eating acid foods doesn't change the pH of the body so won't…
    12 February 2019
  • soloh
    Re: Melting Points for Different Solids
    Could you please practically research whether candle wax can melt at room temperature under reduced pressure?
    6 February 2019
  • asli
    Re: A Bending Bone
    vinegar has acid so if we eat something that contains acid which is bad for bones so what will happen if we eat something that contains Acid!?
    14 January 2019