Temperature is the property of a material that measures the hotness and coldness of the material. The temperature of the material specifies the spontaneous flow of heat; then a question arises: Is temperature a physical quantity?
The temperature of the material is associated with the internal motion of the molecules so that the molecules acquire kinetic energy. As the temperature is concerned with the internal property of the material, we are trying to give why and how is temperature a physical property through this post.
The temperature is a physical property because it only gives the molecules of the material to possess kinetic energy, which causes random motion of the molecules inside the material, but it does not affect the molecular configuration which is associated with the composition. Since there is no change in the composition of the substance due to temperature; hence it is a physical property.
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How Is temperature a physical property?
Each and every material possesses a certain temperature that describes its general property to explain how the temperature is physical by considering the thermometer as an example. The thermometer is a measuring device used to check the temperature of the substance.
The thermometer consists narrow glass tube which has mercury at the bottom of the tube. When the heat is supplied, the mercury expands and acquires kinetic energy and begins to rise. If the temperature falls, the mercury also falls back. In this process, the electronic configuration of the mercury does not change; only the mercury molecules attain kinetic energy causing the internal motion.
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Is change in temperature a physical property?
We cannot predict the temperature of the substance unless a change in physical property occurs. If a substance changes its shape, texture, color, hardness or size by varying the temperature, then we can say that change in temperature is a physical property.
Let us consider the example of iron or steel. Iron is a very hard material, and it is very tough to mold than to give the desired shape. When you heat the iron or steel above 460°C, the iron or steel glows with red color and also becomes soft and easy to mold. The change in the temperature of the iron or steel causes them to change in color and lose hardness, these two changes of iron and steel is nothing but the change in the physical property, which can be reversible when you cool them. Thus the change in temperature is also associated with the physical property.
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How Is a change in temperature a physical property?
Heating and cooling any substance causes a change in the temperature. Since we know that temperature is nothing but the internal motion of the molecule, then arises a doubt that is the temperature a physical property if the internal motion of the molecule changes?
The answer to this question can be specified by considering the example of water. Water boils at 100°C and freezes below 4°C. This boiling and freezing of the water refer to a change in the temperature of the water. When the water boils, the vapors are formed. Here water transformed its state from liquid to gas, but the composition of the water remains the same as the molecule possessing 2-hydrogen and an oxygen atom held by a strong bond. Only the physical state of the molecule is changed. It is the same in the case of the formation of ice from water. When the water freezes below 4°C, the liquid water turns into the ice of solid-state.
In both cases, the change in the temperature is due to the change in the motion of the molecules. If the molecular velocity is considered as the physical property, then change in temperature is also a physical property as the temperature is highly influenced by molecular motion.
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If a chemical compound undergoes a chemical reaction with an increase or decrease in temperature, then how can we say temperature as a physical property?
Basically, chemical reactions are supposed to happen even without changing the temperature. In some compounds, the variation of temperature makes the chemical reaction occur quickly. If you raise the temperature, more heat energy causes the bond with the neighbouring molecule, so the reaction time has reduced. The change in the temperature associated with the molecule only provides more kinetic energy to the molecule and breaks the bond with the neighbour atom. After breaking the bond, the chemical property of the individual atom remains the same. Thus it is also considered as the physical property.
There are some cases in which the chemical reaction causes release the of heat. The release of heat is nothing but a change in the temperature. In that case, a chemical reaction is responsible for the change in the temperature, and the temperature has nothing to do with the chemical reaction; hence the change in temperature, in this case, is also considered as the physical property.
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Frequently Asked Questions
What are factors affect the temperature of the substance?
The factor that affects the temperature of the substance more is the movement of the molecule.
If the motion of the molecule in the substance is more, the kinetic energy acquired by them will be more; this leads to the substance achieving high temperature. If the motion of the molecules is slower, the kinetic energy acquired by them will be less, leading to achieving less temperature.
Does change in temperature cause change in other physical properties?
The change in physical properties and the temperature are always associated with one another. Some time variation in temperature causes changes in the physical property, while on the other hand, the change in physical property leads to a change in temperature.
The change in the temperature is largely influenced by the variation of pressure and volume. This leads to change in the other physical properties such as texture, shape, size, solubility, color, hardness etc. For example, lead chloride. Lead chloride is insoluble in cold water but is soluble in hot water. Here the temperature of the water varied, which led to a change in the solubility of lead chloride.
Why is temperature a physical property?
The temperature of an object is variable and reversible and also always characterizes physical change such as the melting, boiling, freezing point and state of the substance.
Any property associated with the physical appearance, measurement, observable and do not involve in the chemical reaction is called as physical property. Temperature is also a measurable quantity and sensible that specifies a substance’s physical nature.
How do you measure temperature?
There are three units to measure the temperature; they are
- Fahrenheit
- Celsius
- Kelvin
What are the factors that highly affect the physical state of the matters?
There are specific properties of matters which is responsible for the change in the physical state of the matter; they are
- Temperature –increase in the temperature, the matter can be transformed from solid to liquid to gas meanwhile decreasing the temperature a liquid can be turned to solid and gas can turn into liquid.
- Pressure –by increasing the pressure, gas is transformed into a liquid, and liquid can be transformed into a solid. In the case of a decrease in pressure, it is vice versa.
- Intermolecular force –if the intermolecular force between the matter is strong, then the state of the matter will be solid as the intermolecular space between the atoms become very less. If intermolecular force is moderate, then the matter acquires a liquid state, and if it is very much less, then the matter attains a gaseous state as the intermolecular space is too large.
Is temperature an extensive or intensive property?
Temperature is often referred to as the intensive property, as every object possess certain temperature irrespective of shape, size and amount.
The temperature of the substance does not depend on the amount of substance present in it. If you take a cup of milk at 30°C and a cup of water at 30° and if you mix them, the mixture of water and milk also have the same temperature of 30°C.
Also Read:
- Diffusion and temperature
- Is temperature an extensive property
- Melting point and temperature
- How to calculate density at different temperatures
- Boiling point and temperature
- Does dew point increase with temperature
I am Keerthi K Murthy, I have completed post graduation in Physics, with the specialization in the field of solid state physics. I have always consider physics as a fundamental subject which is connected to our daily life. Being a science student I enjoy exploring new things in physics. As a writer my goal is to reach the readers with the simplified manner through my articles.