My son, second grade, is doing states of matter. We were trying to help him label different examples for solid, liquids, and gasses. In his science textbook, it mentions that you can’t see a gas and that steam is a liquid because it’s just water suspended in the air, but on his worksheet, by a different source, has fog and smoke as an example of a gas. I’ve always thought of smoke as a gas on a base level. I understand that there are particles being suspended in the air that you can see, but can someone help the states of matter so I can help my son with his homework.
In: 2
Fog is small liquid water droplets in the air. Water as a gas i invisible.
Look at a t a pot of water you boid on the stove. You can boil away all water and never see anything escaping. That is because it is water as a gas that have left and it is invisible. That is if the air is hot enough like typically indoor air.
If you do that out a cold winter day there can something white that you see leav the pot. That is water too it has just been cooled down by the cool air and considered to small liquid water droplets. So if you cool down water as gas enough it condensate to water as a liquid and you can see it.
You can compare it to the moisture of you own breath, not visible when it is warm but can bee seen a cold day day.
Notice I have not use the word steam there is a reason. Steam have multiple usages. What most people thing of steam is something white that you see is released by for example a old steam locomotive. That is wet steam that is a mixture of water as a gas and water as liquid Droplets. It is the liquid droplets you can see.
There is also dry steam that is just water as a gas ant id it not visible.
It is a bit of a simplification that you can see a gas. Gas particles can interact with light and scatter it. The sky is blue because gas in out atmosphere scatter more blue then red light. The same way water as a gas scatter light.
The smoke from a fire will be liquid and solids. Lets just look at a wood fire. If there is lot of white smoke that will be a result of water and what you can see is water as small liquid droplets. The black/gray smoke you can see will be soot. So small particle of unburned solid material, it will primary just be carbon, that is a result of a uncomplete combustion of the wood.
There will be gases too. When you burn wood the combustion produces are primary carbon dioxide and water. In cold air that water can condeate back to a liquid but in warmer condition you can have a invisible exhaust.
This is if the combustion is complete, if not you will have unburned sooth that you can see. Take a look at [https://youtu.be/07P-6gqYg2g?t=23](https://youtu.be/07P-6gqYg2g?t=23) that show two different burn barrel design where one provide a flow of hot air and you get complete combustion and the other do not. It show the visible smoke is a result of incomplete combustion in dry wood.
Latest Answers