Quiz Time - What does DVD really mean?

Slartybart · 12 May 2015

I'll try to Sherlock it while the cells cycle .. maybe free radical association might hasten my recall.

here goes ...

frozen rock (solid) sinks in liquid rock (lava)
frozen metal (iron) sinks in liquid metal (molten)
frozen water (solid) floats in liquid water (water)

Given the following: 32°F (0°C) / 29.96"Hg, I can deduce that the density of solid water is less than the density of liquid water.

The only other thing that keeps cycling to the forefront is the witch scene from Monty Python's Holy Grail

You would think that water would be easy to burn given all of that Hydrogen and Oxygen.

f14tomcat · 12 May 2015

@Slartybart - Let me know when you've had enough torture, and I'll put you out of your misery! Of course solid water is less dense than liquid water!!! How many icebergs sink to the bottom of the ocean?

Water expands when frozen, giving the same mass in a larger volume = increased buoyancy. The ice does not actually float on the water, rather the water sinks around and under the ice.

f14tomcat · 02 Jun 2015

f14tomcat said:

Ok, a real science quiz question.... standing rule! -- Google-not! No multiple choice, you have to know the answer.

At exactly 32°F (0°C), what unique characteristic do liquid water and ice share?

Answer: they are in "thermal equilibrium". What is thermal equilibrium?

Basically, at exactly 32f/0c, no energy is exchanged. Without an external source of heat energy, ice will not melt. Without an external force removing heat energy, water will not freeze. They are both static at exactly the same temperature. Remember there is no such thing as "cold", only the absence of heat (energy). Pure H2O is assumed, contaminates would alter the static point.

Slartybart · 02 Jun 2015

f14tomcat said:

Answer: they are in "thermal equilibrium". What is thermal equilibrium?

Basically, at exactly 32f/0c, no energy is exchanged. Without an external source of heat energy, ice will not melt. Without an external force removing heat energy, water will not freeze. They are both static at exactly the same temperature. Remember there is no such thing as "cold", only the absence of heat (energy). Pure H2O is assumed, contaminates would alter the static point.

So what makes H20 unique - wouldn't all compounds share this thermal equilibrium characteristic given their melting/freezing temperature?

I might have been thimking this one too hard - not that it would have changed anything over the past three weeks. I still wouldn't have the answer. I did mention the labyrinth didn't I?

Thanks for posting the answer.

Bill
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