I got a question about density.
Okay, as everyone knows, water has a density anomaly, meaning that at 4°C, water has its highest density. That's why water at this temperature would sink to the ground.
Now that is the thing I don't understand. There are two things I don't understand:
1.Water with a temperature of less than 4°C will be above the water having that temperature. Now the kinetic energy of the molecules of the water with 4°C is higher than of water with a lower temperature. Why, then, does it not rise (since Ekin is higher, it can transform more Ekin into potential energy - and due to the Brownian motion, that would probably happen). The same happens with warm air.
2. What's different about the molecules having more density compared to those with less density? They are closer together, but they still have the same mass. Why, then does the "bulk" with higher density sink and the one with less would stay upon? I'm talking about one and the same liquid (or liquids which are soluble).
The same with salt water. Why do not just the ions sink, but the whole water? I've just read about Cold Seeps, that are caused by this phenomenon.
And finally, why is it that in general, all things with lower density than liquid A would flow, and with higher density than A would sink?
Thanks in advance.