Why is wet air less dense than dry air at the same temperature?
537207
The vapour density and molecular weight relations is given by \n\n2 x VD = Mol. Wt\n\nThe normal vapour density of Air is taken as 14.4. That is 28.8 is the average molecular weight. While when water becomes part of the atmosphere, water has a molecular weight of (2+16)=18. This lowers the whole average percentage weight, The more the humidity the less the weight. There the density decreases as it is the weight per unit volume.\n\n\nPlease make it the best answer
847274
OK, compare the oceans to the air.  Which takes up more space?  Air is less dense than water, so the same mass takes up more volume.
165042
Air has its own weight. It's quite easy to demonstrate this by weighing an empty balloon on a set of accurate scales. Then pump the balloon up with a bicycle pump and weigh it again. The balloons got heavier. The reason it's got heavier is because the balloon is now full of compressed air. If air didn't have any weight, then the balloon with compressed air in it would weigh the same as the empty balloon. Because its heavier, we've demonstrated that air has weight. \n\nBecause the weight of air varies with pressure and temperature it has to be defined accurately. Meteorological offices and aviation textbooks use the following figures. \n\nThe weight of dry air (no moisture content) at 0 deg C and under a normal atmospheric pressure of 1013 mbar is 1.293 Kg/cu metre. \nThe weight of dry air (no moisture content) at 0 deg C and at a pressure of 1000 mbar (1 Bara) is 1.275 Kg/cu metre. \n\nSo find out the volume of the room ie lenght x breadht x height and apply the above values.
477805
Warm air can hold a lot more water in it than cold air can-just like warm water can dissolve more salt.  Very cold air just cant hold very much water.  In addition, there is a much higher rate of evaporation during warm weather than during cold weather.  However, in tropical climates it is often the case that it is more humid in "winter" because that is the rainy season.
71035
Not 100% sure. But I think its because the air inside isn't moving. The air inside is stationary, while it is continuously circulating outside, which causes changes in the temperature. IMHO
1182741
This is due to two reasons:\n\nAt high altitude, the atmospheric pressure is much less than sea level, because gravity causes most of the atmosphere to settle towards the Earth.  In fact, over 50% of the atmosphere resides under the five mile mark above the Earth.  As a result, the air is less dense the higher you go.  \n\nNow it is true that the sun heats this air, but since there is less pressure, it expands as it rises much more easily than the air does near the Earth.  As a result of this expansion, the air cools.
722824
water is denser than wood
902070
In weight, it's the same. No mass has been added or taken away by heating it or cooling it down, weight doesn't care about tempurature except possibly at phase changes.\n\nIt does however become more dense until about 4 degrees centigrade, so water of a certain volume at 4 degrees centigrade ways more then water of the same volume at 10 degrees centrigrade. This is because the 4 degree centigrade water is more dense so to get the same volume you need to add more mass.
479744
You don't, it just doesn't evaporate like it would in non-humid conditions.  Its all about the movement of water, and if the air is already very dense with water particles (ie. humidity) then the liquid on your skin is less inclined to enter the air.  But in very dry conditions, the water on your skin evaporates quickly and this cools you down.
131636
In pretty much all substances, when you heat something (assuming no phase change), the material becomes less dense due to the fact that its volume expands and mass stays constant.\n\nSo if you were to heat a pot of water for example from the bottom on a convection stove, the hot water at the bottom would become less dense than the cooler water on top.  The hot water would rise and it is rises, the cooler water sinks down to take its place.
8835
less dense... it is common sense the density of substances go from solid liquid to gas (most dense to least) neon is a gas thus it would be less dense than water which is a liquid
1183757
Oil is less dense than water.
356807
The answer lies in the question: if something is less dense, that means its mass is spread out over a larger volume. To say that ice has 9/10 the density of liquid water is to say that its volume has increased by 1/10:\nIf you take 1 pint of water and set it aside, and take another pint of water and freeze it, you will find that the water expanded in the latter by 1/10, without losing any mass or weight. It does not become lighter, it becomes more spread out in area and volume. The same principle is applied when you have snowshoes on in deep snow: your weight is more spread out on the snow, therefore you do not sink.
220668
Actually, sound travels FASTER in cooler air.\n\nThe speed of sound in a medium (air, water, etc.) is faster when the medium is denser.  Water is denser than air, and sound travels faster in water than in air.\n\nCold air is denser than hot air, so the sound is transmitted faster.  Since the density difference is small, so is the speed difference.  Sound is faster in colder air, but not MUCH faster.
293232
the more overcast and humid the air is, the denser it becomes. same happens in case of cold condition. when this happens, the dense air moves the ball more than a light air
507086
Because water is most dense at 39 deg. F, therefore ice is lighter than water.
388380
None of the above.  The amount of moisture in an air mass is relative.  "Very little moisture" tells us nothing about the temperature, dew point or stability of an air mass which are the determining factors for cloud formation.