Why does liquid rise in a thermometer

Liquid-in-glass thermometer. Mercury the liquid inside thermometer is mercury.. When the liquid in the thermometer gets warmer it expands. This bulb contain the liquid. Sensitivity of a thermometer is the length of increase of the liquid per degree rise in temperature. More sensitive means more noticeable expansion.

So if you want to increase the sensitivity, you could have a thinner capillary tube, a larger thermometer bulb etc. It is the length of increase of the liquid per degree rise in temperature.

The different parts of a liquid thermometer are the plastic strip and heat-sensitive liquid crystals. As the liquid in the thermometer is heated it expands, and the only way the expanding liquid can go is upward. As the liquid in the thermometer cools, it will contract, and the liquid will fall back down into the resevoir, causing the column of liquid to move downward.

A liquid thermometer actually measures the thermal expansion of the liquid mercury. Log in. Study now. See Answer. Best Answer. Study guides. Physics 20 cards. Which term explains whether an object's velocity has increased or decreased over time. Which of these is a characteristic of nonmetals. What is the only factor needed to calculate change in velocity due to acceleration of gravity 9. What term is used to describe splitting a large atomic nucleus into two smaller ones.

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Q: Why does liquid rise in a thermometer? Write your answer Related questions. Why does the liquid level rise in a thermometer when the temperature is higher? How does a liquid thermometer works? What does liquid thermometer do when the liquid is warmed? Why does the liquid level rise in a theremometer when the temperature is higher? This is why the molecules in the thermometer move closer together and down the tube.

Project the image Molecules in A Thermometer. In the drawing, lines have been added to indicate the level of the liquid in each tube. In reality, there is no line. Students should draw circles representing molecules all the way up to the line drawn in each tube. Have students use the projected illustration as a guide as they draw a model of the molecules in a hot and cold thermometer on their activity sheet. The Hot Thermometer illustration should show random circles with more motion lines.

The circles should be a little further apart than in the cold thermometer. The Cold Thermometer should show random circles with fewer motion lines. Project the image Different Thermometers Same Temperature. Tell students that this picture shows two thermometers that are identical in every way, except one has alcohol and the other has mercury inside.

The levels of the alcohol and mercury are shown. After the class discussion, have students write their own response to the question about the two different thermometers on the activity sheet.

The American Chemical Society is dedicated to improving lives through Chemistry. Skip Navigation. Lesson 1. Engage Find out what students know about thermometers. Hold up an alcohol thermometer and ask students: Why do you think the liquid in a thermometer moves up and down when it is heated and cooled?

Students should realize that the movement of the liquid in a thermometer is related to the motion of the molecules of the liquid when they are heated and cooled. Remind students that molecules move faster and a little further apart when they are heated. Molecules also move slower and a little closer together when they are cooled. Give each student an activity sheet. Explore Do an activity to investigate what makes the liquid in a thermometer go up and down. Question to investigate What makes the liquid in a thermometer go up and down?

Put your thumb or finger on the red bulb and see if the red liquid moves in the thin tube. Observe the red liquid in the thermometer when it is heated and cooled. Expected results The red liquid goes up in hot water and down in cold water. Record and discuss student observations Give students time after the activity to record their observations by answering the following questions on their activity sheet.

Based on what you know about the way molecules move in hot liquids, explain why the liquid in the thermometer goes up when heated. But not all thermometers with silver liquid contain mercury. Mercury can be toxic in certain situations. Most oral and rectal thermometers contain about 0. Holding the thermometer upright, slowly and gradually immerse only the bulb of the instrument into a solution of dry ice and alcohol contained in a small lab beaker or another such vertical container.

During this gradual insertion, the mercury should begin to solidify. The accuracy of the measurement is also very high. But the downside is that it takes a little longer to measure body temperature than the first two devices. To get accurate results, be sure to read the instructions carefully. For digital thermometers: Test every six months or so depending on frequency of use to make sure the thermometer works properly, using either the ice water or boiling water method.

Many digital thermometers have reset buttons. If the accuracy is off, adjust the thermometer to the proper temperature using this button. The mercury will rise to the top of the thermometer and join together. Allow the thermometer to gradually cool down to room temperature. If you need to take several attempts, just heat and cool gradually. Do not overheat, as the thermometer could burst. Heating—Heating the thermometer bulb is often the quickest and most successful method of repairing column separations.

The heat can be applied by holding the bulb under a faucet of hot running water or by immersion in a pan of slowly heating water. Sprinkle sulfur powder over the contaminated area and rub it gently all over the surface and into the cracks with a paper towel.

Sulfur powder binds with mercury. Use a paper towel dampened with water followed by wiping with another damp paper towel to clean up the sulfur and mercury. If you touch it, a small amount may pass through your skin, but not usually enough to harm you.

Alcohols applied to the skin are used to disinfect skin before a needle stick and before surgery. They may be used both to disinfect the skin of the person and the hands of the healthcare providers. Insert the tube into the storm glass until it reaches the bottom of the bulb. Slowly pump the liquid out until all of the liquid is gone. The Galileo thermometer consists of a sealed glass tube that is filled with water and several floating bubbles.

Galileo thermometers work on the principle of buoyancy, which determines whether objects float or sink.