Re: Granite countertops. Radioactive?

[Jerome Meekings]

Jerome;

> > What Fred was talking about is that O2 at one atmosphere and 100% > concentration is toxic. This is why the maximum depth for scuba divers > using standard air mix is 300 feet. The partial pressure of atmospheric > oxygen is 14.7 pounds per square inch at that depth. This is the > equivalent of 100% concentration at sea level.

That was the one we were talking about, though I don't think Fred got the point that it was one component not both.

And the usual limit for most scuba divers is 130 feet or 40 Meters, not

91 Meters 300 feet. For that it is usual to have a 3rd gas "He" in the mix.

But that is getting too complex and loosing the point of the joke.

[Jerome Meekings]

It is the pure element gas Nagel and I were talking about, but not the compound one you were. ;-)

[Fred the Red Shirt]

No, we were talking about 'dihydrogen oxide', aka 'hydrogen hydroxide', aka H20, aka water. If you breathe water you die. If you are exposed to water in gaseous form at one bar partial pressure, you are scaled to death.

From your two component comment it would appear you thought we were talking about air.

Well, yes. We were talking about water, not air.

[Fred the Red Shirt]

Well, yes. Kate referred to 'one component' of it. The rest of us stayed on-topic, or should that be off-topic, or maybe on the off-topic?

[David G. Nagel]

The practical depth for nonprofessional scuba divers is about 100-150 feet as you say. This has more to do with the ability to handle the depth than anything else. The MAX depth for any diver using O2-N2 mix is

300 feet period. At that depth the partial pressure of O2 is 14.7 pounds per square inch which is lethal.

Dave