2007-04-12 09:21:28 · 8 answers · asked by donkeypunch'em 3 in Science & Mathematics ➔ Chemistry
Because mercury is much denser (heavier) than water. Water is so much lighter that a water barometer would have to be about 30 feet tall; a mercury barometer is about 30 inches.
2007-04-12 09:26:06 · answer #1 · answered by computerguy103 6 · 1⤊ 0⤋
The density on Mercury is much greater than water so a Mercury barometer will fit in a room but a water one would be 25 - 30 feet tall.
2007-04-12 09:36:11 · answer #2 · answered by TBU 2 · 0⤊ 0⤋
They use both. Mercury is only toxic in certian states such as a gas. Mercury is not used in Thermometers anymore because of the toxic levels, but since a barometer isn't used in the mouth they still use it.
2007-04-12 09:30:01 · answer #3 · answered by Baritonegirl 1 · 0⤊ 0⤋
Don't forget about the vapor pressure of water. The sealed end of the barometer is effectively a vacuum. Water in a barometer will constantly be evaporating into the vacuum seriously affecting the accuracy of your reading
2007-04-12 09:37:24 · answer #4 · answered by dogsafire 7 · 0⤊ 0⤋
Because it has a different reaction than water does to the heat and is needed in order to make the difference in the barometer
2007-04-12 09:30:11 · answer #5 · answered by hereforyou 2 · 0⤊ 0⤋
because pressure changes in water won't allow a barometer to reflect pressure of the air
2007-04-12 09:24:46 · answer #6 · answered by wizjp 7 · 0⤊ 2⤋
I reckon years ago no one knew just how toxic it is.
2007-04-12 09:37:59 · answer #7 · answered by fatboycool 4 · 0⤊ 0⤋
weight per unit volume
2007-04-12 09:25:56 · answer #8 · answered by Anonymous · 1⤊ 0⤋