Why is steam produced before water reaches 100 degrees C?

[Christmas themed thank]

Water boils at 100 degrees C and steam is produced.

How come if I leave the shower running the room steams up from condensation build up then? For water to rise, it would have to be steam - the shower definitely does not reach 100 degrees C.

Can somebody explain?

 

[cheesyboy]

Evaporation doesn't only happen at 100c

 

[dirtychinchilla]

My guess is that if the overall temperature of the water is under 100C, then some of it may well be at 100C, which then evaporates. I doubt the temperature of every molecule or whatever is 100C.

 

[Tefal]

Water boils at 100 degrees C and steam is produced.

How come if I leave the shower running the room steams up from condensation build up then? For water to rise, it would have to be steam - the shower definitely does not reach 100 degrees C.

Can somebody explain?

if you can see it it's not officially steam.
its water suspended in the air not gaseous water.

 

[Christmas themed thank]

So before 100 degrees C the water is already less dense than the air and therefore it can rise?

 

[radderfire]

Running the hot water will increase the humidity and temperature of the air, making water more likely to condense on relatively cold surfaces such as shower glass.

 

[chaparral]

Can somebody explain?

Same as the steam/mist you get when you breath out when it cold.....

 

[DJMK4]

How do you think steam works for those that happen to pee outside on a cold winters day?

Thats how it works

Science

 

[spookywillow]

Its not steam, It's water vapour.

It's called evaporative cooling.

 

[AshD93]

Steam is invisible, you're seeing waper vapour where steam has condensed.

 

[Christmas themed thank]

Wait so water isn't steam?

 

[Woden]

Also, temperature isn't a fixed point, even in a liquid. It is a bell curve with most of the water at, say, 90c, but some will be lower, and the bits evaporating are higher.

 

[Christmas themed thank]

Can water be plasma?

 

[monkentage]

Water temperature is an average. Some of the molecules will be hotter than others

 

[Freakbro]

Wait so water isn't steam?

The confusion comes because commonly we refer to the mist of water vapour you see as 'steam' but in scientific terms, 'steam' is the gaseous form of water, which is invisible.

So yes, water at 100*C does turn into steam, but at cooler temperatures what you actually see are water droplets suspended in the air.

 

[Tefal]

Can water be plasma?

dont know about plasma but it can be a supercritiacl fluid where it's no longer distinguishable between gas or liquid and has the properties of both.

and while in this state at extremely high temperature and pressure it will oxidise damn near anything and is used to safely destroy chemical weapons.

 

[Amp34]

So before 100 degrees C the water is already less dense than the air and therefore it can rise?

Or is it the convection currents created by the heat moving the air around, with suspended water particles? Basically like sea spray in a storm, just less energetic.

 

[jsmoke]

Why is the sky blue?

 

[Nitefly]

Why is the sky blue?

For the same reason that the OcUK forums are blue

 

[Tuppy_Glossop]

Boiling point depends on the air pressure above the liquid. Hilary found that tea tasted insipid when they brewed up on Everest. This is because the water boiled at a lower temp due to low air pressure and optimum tea extraction occurs at 100 degrees centigrade.

As others have said, some water molecules have the right trajectory and enough energy to break surface tension at temps lower than boiling. The only temp at which we can be 100% certain that no water escapes is at absolute zero. The number of molecules escaping increases relative to the temperature until all the water has evaporated (crossed from liquid to gas in the phase-state diagram).

The sky is blue because God likes a bit of pr0n.