Why Does Mercury Rise In A Thermometer


Why Does Mercury Rise In A Thermometer?

The mercury pools in the bulb but when it heats up it expands. Because it can’t expand through the bottom of the bulb it is forced up the tube. That expansion caused by the atoms flying around faster and taking up more space is what makes the thermometer work.

What is the reason for the rise of the mercury thread in the thermometer when the bulb is dipped in hot water?

It consists of a bulb containing mercury which is then attached to a narrow glass tube. As temperature rises the level of mercury in the tube increases. This happens because the volume of mercury slightly increases with temperature.

How does mercury or alcohol rise up in a thermometer?

A thermometer has a glass tube sealed at both ends and is partly filled with a liquid like mercury or alcohol. As the temperature around the thermometer’s bulb heats up the liquid rises in the glass tube. When it is hot the liquid inside the thermometer will expand and rise in the tube.

What happens to the mercury when a thermometer?

“When a mercury thermometer breaks the mercury spilled starts vaporising immediately in temperatures of 22-24 degrees Celsius. The vapours can be inhaled by anyone in the vicinity. It goes straight into the lungs and into the blood and the brain. It is very dangerous.

Why does a liquid rise in a thermometer?

The liquid in the thermometer goes up when the thermometer is heated because heating makes the alcohol molecules of the liquid move faster. The extra speed of the molecules competes with their attraction for one another and causes them to move slightly further apart.

What states have banned mercury thermometers?

As a result a number of states have banned or limited the sale of mercury thermometers including California Oregon Rhode Island Maine Maryland Indiana Minnesota and New Hampshire.

Why are mercury thermometers no longer used?

The reason: Mercury released into the environment from a broken thermometer is highly poisonous. … So government and state agencies have mounted campaigns to end the use of thermometers that contain the liquid metal. Federal and state authorities have lobbied since 2002 for bans on medical mercury thermometers.

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Why does the mercury not fall or rise in a clinical thermometer?

The mercury does not fall or rise in a clinical thermometer when taken out of the mouth because of the presence of kink. It prevents mercury level from falling on its own.

Why is it better to take an alcohol thermometer instead of a mercury thermometer while you travel to the mountain region?

Mercury has a greater coefficient of thermal expansion than alcohol. This means a column of mercury will expand and rise more than a column of alcohol for the same temperature change. As a result you can get finer readings with mercury. … Mercury is poisonous and a broken thermometer in the mouth is not good.

Why do thermometers use alcohol instead of mercury?

Alcohol thermometers are used rather than mercury thermometers in very cold regions because alcohol has a lower freezing point than mercury. Pure ethanol freezes at -115 degrees C while mercury freezes at -38 degrees C. Thermometers rely upon thermal expansion of the liquid in a bulb at the base of a thin glass tube.

When did thermometers stop using mercury?

Those days have passed. Since 2001 20 states have banned mercury “fever thermometers” for medical use and regulations tighten every year. Many pharmacies now carry only sterile digital replacements or the less accurate ones with red glop in the bulb.

How toxic is mercury from a thermometer?

The small silvery ball in a mercury thermometer can be dangerous if the glass breaks and the mercury is not cleaned up properly. The mercury will evaporate and can contaminate the surrounding air and become toxic to humans and wildlife. 5-1.5 grams of mercury. …

Do mercury thermometers lose accuracy?

Mercury thermometers cannot be adjusted after calibration. The actual temperature must be calculated by applying corrections to the measured temperature. … A digital thermometer does the math for you—the displayed temperature accurately represents the actual measured temperature.

Does a thermometer have mercury?

The oldest thermometers used are mercury in glass. Newer thermometers include non-mercury liquids in glass and digital and electronic devices that use sensors to measure temperature. Thermometers that check body temperature in the ear across the forehead or have a digital display do not contain mercury.

Why does liquid rise in a thermometer quizlet?

Terms in this set (19) friction causes the object to heat up. why does liquid rise in a thermometer? … absorb heat.

Why is mercury in a thermometer stored in a narrow tube?

Why is the mercury in a thermometer stored in a narrow tube? Mercury thermometers. … This is because a small expansion of the mercury in the bulb will cause a big change in the length of the mercury thread. The bulb is made of thin glass so that heat can be conducted quickly to the liquid.

Do they sell mercury thermometers anymore?

What Will Replace Them? The National Institute of Standards and Technology (NIST) announced last week that it would stop calibrating mercury thermometers starting March 1 a move that brings the U.S. one step closer to phasing out these temperature-measuring devices for good.

What happens if mercury touches your skin?

Mercury is a very toxic or poisonous substance that people can be exposed to in several ways. If it is swallowed like from a broken thermometer it mostly passes through your body and very little is absorbed. If you touch it a small amount may pass through your skin but not usually enough to harm you.

Why are glass thermometers rarely used today?

why are glass thermometers rarely used today? it contains mercury which is a dangerous element. Threat of mercury spills and leak. … Then the thermometer can be rotated until the mercury column can be seen inside the glass rod.

Are mercury thermometers more accurate than digital?

Both laboratory and clinical studies show that there is no significant difference in the average accuracy of the two types of thermometers however there is a greater fluctuation of readings of temperature when using electronic thermometers.

Are mercury thermometers worth anything?

It is the most accurate mercury thermometer ever invented ” she said. … The entire collection of 18th-century thermometers could be worth up to $50 000 but “antique thermometers are only rarely available for sale so it’s hard to get a handle on the exact value ” she said.

Are mercury thermometers more accurate than alcohol?

It is more durable than alcohol thermometer because mercury does not evaporate easily. It is smaller in size as compared to alcohol one. Mercury does not wet the wall of the thermometer which means that results can be highly accurate.

Why does the mercury not fall or rise in a clinical thermometer when taken out of the mouth in Brainly?

In clinical thermometers there is a small bent at the bottom of the tube containing mercury. It is called a kink. The kink prevents the mercury level from falling down on its own. Due to this the temperature does not decrease immediately after removing the thermometer from the mouth.

Why is there no kink in laboratory thermometer?

Usually the function of the kink in the thermometer is to break the flowing connection of mercury in the capillary and the bulb area at the lower end of thermometer. In laboratory thermometer the temperature is measured continuously to note temperature change. … Therefore a laboratory thermometer does not have a kink.

How does the laboratory thermometer differ from the clinical thermometer?

A clinical Thermometer is meant for clinical purposes. It is developed for measuring the human body temperature. A laboratory thermometer which is colloquially known as the lab thermometer is used for measuring temperatures other than the human body temperature.

Why a thermometer is never kept in direct sunlight?

Answer: A normal thermometer can not be used to measure temperature of sun as both are very far away from each other. If the thermometer is kept in direct sun for a longer period of time the temperature of its sensor will increase due to direct heat radiation from sun falling on it.

Why alcohol is not used in clinical thermometer?

Alcohol is not used in a clinical thermometer. It cannot measure the high temperatures because of its low boiling point. Mercury is used in a clinical thermometer.

What is used in thermometers now instead of mercury?

Ethanol-filled thermometers are used in preference to mercury for meteorological measurements of minimum temperatures and can be used down to −70 °C (−94 °F). The physical limitation of the ability of a thermometer to measure low temperature is the freezing point of the liquid used.

Can thermometers be wrong?

No thermometer will provide accurate results if it’s used incorrectly. Never use a thermometer on a person that is meant for another purpose such as a laboratory or meat thermometer. These won’t provide accurate readings.

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What type of mercury is in thermometers?

Elemental or metallic mercury is used in mercury thermometers and (in combination with silver and other metals) in dental amalgam. In China dental amalgam was used to fill teeth over 1000 years ago (cited in Drexler 1998). Inorganic mercury e.g. mercury chloride has been used as a disinfectant.

Do red thermometers have mercury?

How can I tell if my thermometer has mercury? Mercury is a silver-white to gray substance. If your thermometer is filled with a red liquid your thermometer contains red dyed alcohol or mineral spirits and not mercury. These are safer alternatives to mercury fever thermometers.

How do you remove mercury from a thermometer?

Slowly and carefully squeeze mercury onto a damp paper towel. Alternatively use two pieces of cardboard paper to roll the mercury beads onto the paper towel or into the bag. Place the paper towel in a zip locking bag and secure. Make sure to label the bag as directed by your local health or fire department.

How do you reduce mercury in a thermometer?

Firmly grasp the thermometer near the top so that the bulb containing the mercury (or other indicating fluid) is pointed downward. Rapidly move the thermometer down and sharply reverse direction (and snap the wrist upward). When the thermometer reaches the lowest point of the stroke several times.

How would you dispose of the mercury if a thermometer breaks?

The preferred method of disposal for unbroken mercury thermometers and the mercury from broken thermometers is to take them to a local household hazardous waste collection facility or thermometer collection site if one is available in your area.

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