What causes the liquid to move in a thermometer?
When the liquid in the thermometer gets warmer it expands.
When the liquid is heated (by the environment), the particles in the liquid have more energy, and start moving around more, which causes the liquid to expand and take up more room. Conversely, in cold temperatures, the particles do not have as much energy, and do not move as much, so the liquid contracts.
When the temperature increases the particles of the liquid inside a thermometer begin to move faster and what else?
Heat is transferred thru the glass of the thermometer to or from the liquid (mercury) inside. The heat causes the liquid to either expand (hot) or contract. Since the large bulb end contains most of the liquid, but grass doesn't expand as much as the liquid, the expanding liquid forces itself up (if hot) into the narrow tube, which indicated the temperature. On the molecular level, particles outside the thermometer have a certain kinetic energy…
The liquid inside the thermometer "contracts" when it is placed into something cold. This means that it decreases in volume and increases in density. This is the reason that the thermometer can measure heat: the volume of the liquid inside the thermometer changes as a function of heat, and the amount of liquid in the "tube" of the thermometer changes as a function of volume. Because of this relationship, the level of the liquid in…
It doesn't 'move' exactly, it expands. Originally mercury (a metal in a liquid state at room temperature) was used in thermometers; as the the temperature increases the mercury (or other liquid) expands, taking up more of the volume within the thermometer, causing the level to rise. Thermometers are calibrated to allow the temperature to be measured based on how much expansion has taken place.
Typical Liquid in Glass Thermometers (air and body temperature) Molecules moving around the thermometer impart energy to the liquid inside, increasing its own energy, or heat. The heat causes the expansion of the liquid, which rises up the tube. The molecules in contact with the thermometer can also absorb energy from the molecules of the liquid, which will cause the liquid to contract, and move down in the tube. (The glass tube has little friction…
When the liquid in the thermometer gets warmer it expands. This means its volume increases. The only place for the extra volume to go is up the tube, so the level of liquid rises. When the liquid gets colder it contracts (reduces in volume) so it moves back down the tube. See http://www.energyquest.ca.gov/how_it_works/thermometer.html
Place the thermometer in the liquid you are measuring. Wait until the temperature stabilizes, and then read the thermometer at eye level, just like you would a graduated cylinder, except that there's no meniscus. If you are measuring a liquid that is being heated over a Bunsen burner, you should have the thermometer held in place with a thermometer clamp. You should have the thermometer positioned about halfway down in the liquid.