Two Hydrogen atoms covalently bonded to one Oxygen atom. One of the more common compounds on the surface of the earth.

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4
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2answers
133 views

Water bombing - risks and possibilities

I just saw a video on youtube, where an excavator drops a load of water on a car, destroying it completely. I also saw a video with a fire-fighting plane dropping even more water on a burning truck. I ...
-2
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2answers
145 views

Is pure water electrically conductive? [closed]

I know that water with some ions dissolved is a good conductor. I wonder whether it is true for pure water?
0
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1answer
87 views

Paper Napkin Folded

Why folded napkins are better absorbing water than ordinary napkin. I think there must be related to cohesion of water element. Water are captivated between layers because they appeals each other or ...
0
votes
0answers
29 views

What do water stains make things appear dark? [duplicate]

If a piece of grey tarmac is damp after the rain, it appears darker. If I spill water on my carpet, the damp patch is darker than the rest of the carpet. Generally speaking, a lot of things appear ...
4
votes
3answers
2k views

Why does water reflect light?

Why does water reflect light? What is actually happening when light is reflected by water? We know why metals reflect light; water, however, is not metal, but it still reflects light and we can see ...
0
votes
1answer
48 views

How long can water hold elevated pressure and energy after opening pressure cooker lid?

I noticed today that the water warmed up in pressure cooker (1.5 ATM) dissolves sugar much faster and much more than water cooked in 1 ATM. I am interested in how long can water hold the high ...
2
votes
2answers
84 views

Is it possible to mix a drink with a non-standard phase of ice?

Would it be possible to safely cool and drink a glass of water with anything else than the Ih form of ice? Here and here you can see that some alternative forms of ice have a higher density than ...
1
vote
1answer
105 views

Why does water boil differently in a microwave than over a flame?

Over a flame, small bubbles will start to form on the bottom of the pot, and as the average temperature rises, the bubbles will become larger until they start rise to the top. As it gets even hotter, ...
1
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2answers
128 views

movement of water in plants

Books say that water moves from places with a high water potential to places with a low water potential. The movement of water in plants are explained because water potential is lowest in leaves and ...
2
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0answers
92 views

Suction from flowing water

My memory from physics says yes but I want to check. Our pool is dirty and our vacuum is broken. If I were to stick the vacuum hose into the pool drain, would the flow of water going into the drain ...
0
votes
1answer
150 views

How does a water-steam mixture behave?

Namely, if I mix a flow of steam that has density $\rho_s$, velocity $v_s$, and pressure $P_s$ with a flow of water that has pressure $P_w$, velocity $v_w$, and density $\rho_w$, how can I find the ...
2
votes
1answer
95 views

Why does water remain as a “hemispherical bubble” when it falls on a page?

Today while drinking water, a drop of it accidentally felt on a page of my book, and I was thinking that, "Oh my god! The water will spread instantly, making the part of page wet". But, I observed, ...
63
votes
7answers
12k views

When I boil a kettle, what stops all the water from turning (exploding!) in to steam in one go once it reaches 100°C?

While making a cup of tea in the office kitchen, a colleague asked me this question and neither of us could answer with any certainty. We're guessing it has something to do with the pressure of the ...
4
votes
3answers
1k views

Why is boiling not just a surface phenomenon?

The boiling point of a liquid is defined as The temperature at which the vapor pressure of the liquid is equal to the external atmospheric pressure. That being the case, why, in a pot of boiling ...
12
votes
3answers
284 views

Crown shape in water waves?

Watching this slow motion video of waves caused by a droplet falling on water, I am puzzled by the first wave shape. The first wave rises with circular symmetry as I expected, but is not even in ...
3
votes
1answer
200 views

Calculation of long-range forces in Molecular Dynamics - Ewald summation

I am trying to write a code to calculate the potential and forces, for the same using ewald summation.For this purpose, the formula for potential and force I have used is : $$ U = U^{(r)} + U^{(k)} +...
0
votes
3answers
30 views

Breathe Air from a source without any pressure compensation?

I just thought about what I'd do if I was on a sinking ship and of course breathing was the first thing that came into my consideration. Now imagine the ship's front going up and the room you are in ...
0
votes
1answer
252 views

What wavelength of light is the least absorbed by water?

As I understand it, an infrared laser range finder will not work underwater because the infrared rays are heavily absorbed by water. What wavelength (optical, ultraviolet, microwave, etc.) of light ...
2
votes
1answer
90 views

Why is it that not the entire surface of Earth is covered by water? [closed]

Isn't it a coincidence that our planet is mostly but not completely covered by water? Is there a reason why less water or more water is not compatible with intelligent life? Also, isn't it a ...
0
votes
3answers
405 views

Does ice made out of salt water melt slower than ice made of pure water?

I'm trying to make this whole bunch of ice bottles to cool down my little aquarium. What I want in the ice bottles is that, fter freezing the whole bottle full water into ice, I need the ice to melt ...
9
votes
2answers
479 views

Water evaporation problem. Exercise from Feynman's lectures

I read lectures of Richard Feynman and try to solve problems and I have some trouble with a problem on water evaporation. A glass full of water is left standing on an average outdoor window in ...
3
votes
1answer
435 views

Why does water get significantly colder while falling through the air?

I think we've all experienced this effect. You turn on the shower and the stream of water at the shower head is a fair bit hotter than the water towards the bottom of the stream. Alternatively, if you ...
0
votes
1answer
133 views

Can capilliary action move liquid against gravity?

I was wondering if it was at all possible to very slowly suck up water from a cup with a rope, and then deposit the water into another cup on a 3cm thick book or similar object. Here is an example ...
0
votes
3answers
76 views

Kayaking against the wind is faster than with wind in my back? [closed]

Today I was kayaking on a lake. I noticed that there is not very strong, but noticeable wind. There were also currents, all going in one direction, probably caused by wind. One more thing I realized ...
2
votes
2answers
943 views

Why does a paper towel absorb water upwards?

When I touch a paper towel to a drop of water I can see the water move upwards into the paper towel. What force is responsible for this gravity defying phenomenon?
0
votes
1answer
76 views

Efficiency of a gravity feed hose

If I am trying to fill a large cylindrical container with a gravity feed hose, would it be more efficient, time-wise, to drill a hole in the bottom of the container for a greater initial pressure ...
0
votes
1answer
1k views

Why does surface tension of water-ethanol binary mixture decrease with increasing concentration of ethanol?

I was thinking that it must be due to weaker hydrogen bonding in ethanol than in water. But then I learnt that Raman Spectroscopy and viscosity measurements suggest that upto a certain ethanol ...
0
votes
1answer
42 views

Why toilet paper is softer in moist air? [duplicate]

After a hot shower,the air from the bathroom is full of water steam,right? How does the air affect the texture of the toilet paper?I mean,the toilet paper it seems to be softer,but why? Can someone ...
0
votes
0answers
45 views

How long does it take for disturbed water to stop making sound?

Suppose I have a bowl with water or another liquid. The water from the bowl is perfectly quiet. Then I throw a stone in the water and I wait. How can I calculate the time after which the water is ...
1
vote
2answers
135 views

Greater pressure perceived when wearing waders

A few days ago I went for a hike in the waters of a river. I was wearing waders like the ones you see in the following picture: I don't understand why the pressure I perceived on my legs when the ...
1
vote
0answers
30 views

Can I disperse a droplet with electromagnetic fields?

If I have a droplet of water, can I apply an electromagnetic field in order to disperse the droplet into smaller subdroplets (tiny vapor) and fill a space with them? The same way that magnetic dust ...
0
votes
2answers
55 views

When drying paint brushes washed with water, which way is the best to orient them?

After washing my paint brushes with soap and water and rinsing them, in order to avoid damage to the bristles and the ferrules and the wooden handle, is it best to hang them bristles down and let ...
0
votes
1answer
108 views

How does sound make water flow in zig-zag patterns?

I saw this video where water is piped past a large speaker and weird shapes are formed. Later in the video the pipe actually moves from the sound so that's obviously why the patterns are forming, but ...
3
votes
1answer
165 views

Why doesn't water get 'increasingly thicker' as it gets colder?

It's my understanding that the colder liquids get (or anything else for that matter) the slower the constituting particles move. That being the case, why is H$_2$O either 'water' or 'ice'? Given that ...
1
vote
1answer
92 views

How to calculate the resistance (conductance) between two contacts embedded into a 3D object?

Pouillet's law, $R = \rho \frac{\ell}{A}$, is useful when dealing with a "column" (cylinder) of a conducting material, with cross section $A$ and height $\ell$. Using this equation has an underlying ...
3
votes
4answers
451 views

Is a turbine the same thing as a motor?

Is a turbine the same thing as a motor? We know that water, wind and nuclear power plants rotate a turbine so is this turbine like a motor? I think we can generate electricity by rotating a motor too. ...
-1
votes
1answer
96 views

Boiling water function

i want to make a program that realistically boils water with all the variables but know near nothing about the math i got the energy transfer equation down but this seems to be giving me some ...
-2
votes
2answers
266 views

Why can't people just pump water from ground and flood deserts to make them habitable? [closed]

I know this may be the wrong site, but I'm a curious man and I want to solve world's problems. One of big problems is deserts. They're so dry that nothing grows there. I was thinking about this and ...
4
votes
3answers
416 views

Does wax go through a sharp phase transition when it melts?

When ice melts, the system goes sharply from being solid to being liquid. There is no intermediate state where it is soft. This is a true phase transition. The thermodynamic potential is not an ...
1
vote
0answers
36 views

Difference between a tap and a hosepipe

When the flow of water through a tap is blocked by the fingers, the water does not increase in velocity whereas the velocity of water increases when the same is done tp a hosepipe. Both involve the ...
5
votes
1answer
2k views

Does an ice cube change its core temperature as it melts?

Let's say we have an ice water solution in an ambience with room temperature, i.e. there is a permanent exchange of energy. Let's suppose the ice cubes were from the freezer, which is at $-18°C$. The ...
5
votes
1answer
339 views

Why do I sink then float in a swimming pool?

Was swimming this morning and observed something strange: if I stop treading water, hold my legs together, arms pressed against my sides, then I sink to about 3m below the surface, and then rise again ...
0
votes
0answers
80 views

Does the density of water ice (any form of water ice) near 0K exceed the density of water at 277.15K?

In a question brought up by my chemistry class, the most we have determined is that the stability of most forms of ice decreases as the temperature decreases. What does this loss of stability do to ...
2
votes
2answers
115 views

Will the water go inside the moving water bottle?

Let's say that there is a empty bottle in the water moving at a high speed like this: My question is: Will the water go inside the the empty bottle when the bottle is moving at a high speed? If yes,...
0
votes
0answers
49 views

What will be the affect of Global Warming if Polar Ice melts? [duplicate]

Due to global warming, all the polar ice melts & sea level increases, with increase in humidity. Angular momentum of ice at pole is, very low. Due to shift of water, from pole to equator, it's ...
15
votes
3answers
1k views

Why do the waters of the different oceans of the world have different ratios of their H and O isotopes?

I was reading about the Kelvin, then water, which defines it, so I ended up reading about the VSMOW. It's based on "average" ocean water. From https://en.wikipedia.org/wiki/...
2
votes
1answer
73 views

If you charge water will the evaporation rate change?

If you take away electrons or add electrons to a body of water will the evaporation rate be changed? (Even if it's brief or the effect is small)
9
votes
1answer
985 views

Why is ice more reflective than liquid water?

Why is ice more reflective (has higher albedo) than liquid water? They're both the same substance (water). Is something quantum mechanical involved?
0
votes
1answer
41 views

What granular/colored material suspends itself in an enclosed container filled with water regardless of pressure, gravity and buoyancy?

i've been looking around for an answer but it turns out that google dsn't think it's an obvious question. Would really appreciate the help. Basically i'm wondering if there is any known material that ...
0
votes
1answer
124 views

Water enclosed in a vessel

Suppose I am taking water in a glass or metal or even something else. It s air tight and (so it is water tight). Now imagine, if I keep it heating and none of its molecule escapes from it, what am I ...