2007-02-21 00:25:47 · 11 answers · asked by vk 1 in Science & Mathematics ➔ Biology
the mercury is a liquid metal which conducts heat.that's is why it rises up
2007-02-21 01:57:44 · answer #1 · answered by sabari.g .girish 2 · 0⤊ 0⤋
Both mercury (a liquid) and glass (a solid) expand when heated but mercury expands much more than glass. If you heat a quantity of mercury in a glass bulb some of the mercury will spill over. If you confine the spilled mercury within a very narrow hair-like channel in the glass stem of a thermometer, the excess mercury will travel up the stem which can be calibrated against lab references to indicate the temperature. By properly shaping the glass stem it can be used to magnify the very small mercury channel as in an oral thermometer. An oral thermometer also contains a 'glitch' near the bulb that prevents the mercury column from retreating after taking a temperature and you must 'sling' the thermometer to send the mercury back down into the bulb before the next reading.
2007-02-21 01:03:58 · answer #2 · answered by Kes 7 · 0⤊ 0⤋
A mercury-in-glass thermometer, invented by German physicist Daniel Gabriel Fahrenheit, is a thermometer consisting of mercury in a glass tube. Calibrated marks on the tube allow the temperature to be read by the length of the mercury within the tube, which varies according to the temperature. To increase the sensitivity, there is usually a bulb of mercury at the end of the thermometer which contains most of the mercury; expansion and contraction of this volume of mercury is then amplified in the much narrower bore of the tube. The space above the mercury may be filled with nitrogen or it may be a vacuum.
2007-02-21 00:35:22 · answer #3 · answered by gilbert92405 1 · 0⤊ 0⤋
Everything expands and contracts based on the temperature. Mercury, a metal that is liquid at room temperature, is no different. If you look closely, you will notice that you have to look at the thermometer at just the right angle to see it. That is because the room for expansion is so little.
As some extra information, I think, just speculating, that mercury was chosen because of its melting and boiling points. It won't freeze until -40 (which just happens to be where F and C meet) and you don't want to be around when it turns to a vapor. But, then again, I don't know aobut you, but if it's cold enough to freeze mercury, its cold enough to go to Florida, or Hawaii!
2007-02-21 00:37:08 · answer #4 · answered by Anonymous · 0⤊ 0⤋
Mercury rises in a thermometer because as it gets warmer, it expands, and the only way to go is up. The pressure inside the thermometer is low enough not to impede its rising.
2007-02-21 00:33:32 · answer #5 · answered by Anonymous · 0⤊ 0⤋
When temperature goes up the mercury expands but it cannot go any place but up, if you put a thermometer on the side it will go to the side. Reverse happens when the temperature drops.
2007-02-21 00:33:14 · answer #6 · answered by minootoo 7 · 0⤊ 0⤋
it expands when heated, contracts when cooled. When the air is warmer it displaces a larger volume and hence, rises in the tube. It is consistent in the amount it expands given a specific temperature, so we can place markings next to the tube which corresponds to the temperature at that expansion.
2007-02-21 00:29:27 · answer #7 · answered by Shredded Cottage Cheese 6 · 0⤊ 0⤋
when heat is given to mercury then expands so in case of thermometer when temp rises, it expands and move upward in the tube
2007-02-21 21:05:36 · answer #8 · answered by PearL 4 · 0⤊ 0⤋
when there is heat, the mercury is very sensitive and it expands and moves up the tube; it cannot move down unless it contracts
2007-02-21 00:28:40 · answer #9 · answered by pigley 4 · 0⤊ 0⤋
as mercury has very low temperature, it rises up.
2007-02-21 00:36:40 · answer #10 · answered by ashutosh agarwal 2 · 0⤊ 0⤋