# How can the particle model of matter help us understand expansion and contraction of substances?

## How can the particle model of matter help us understand expansion and contraction of substances?

When substances expand or contract, their particles stay the same size. It is the space between the particles that changes: the particles in a solid vibrate more when it is heated, and take up more room. the particles in a gas move more quickly in all directions when it is heated, and take up more room.

## What determines the expansion or contraction of materials?

Materials expand or contract when subjected to changes in temperature. Most materials expand when they are heated, and contract when they are cooled. When free to deform, concrete will expand or contract due to fluctuations in temperature.

How can heat expansion be useful?

The difference in expansion causes the bimetallic strip to bend when the temperature is changed. This movement has many common uses including: thermostats to control temperature, oven thermometers to measure temperature, and switches to regulate toasters.

What do you understand by expansion and contraction How are the three states are related to them?

Substances expand (increase in size) when they get warmer, and they contract (decrease in size) when they get cooler. This property can be useful. For example: Thermometers work because the liquid inside them expands and rises up the tube when it gets hotter.

### How is contraction different from expansion explain with an example?

1. The increase in the size of an object on heating is called expansion whereas, the decrease in size of an object on cooling is called contraction. 2. An example of an expansion is an extra three rooms built onto a house whereas, An example of contraction in a liquid is a thermometer.

### Will the expansion and contraction of matter be harmful to the structure of buildings give your opinion?

You might note that expansion/contraction by itself is not problem; it is differential expansion/contraction that generates internal forces. If a building uses the same material for structural features, then there are no differential forces.

What are some other examples where objects are designed to allow for expansion and contraction?

Applications of Expansion and Contraction The jammed metal lid of a jam jar can be opened by heating. The jar is inverted and just the lid is dipped in hot water. After some time, the lid can be opened easily as the lid gets slightly expanded. The fact that materials expand on heating is used in thermometers.

Why does a substance expand when heated?

When a substance is heated, its molecular movement increases. Due to this, the average distance between the molecules also increases, thereby increasing the volume of the substance, i.e., expanding the substance.

#### What is the effect of expansion and contraction due to heat in welding?

Distortion in a weld results from the expansion and contraction of the weld metal and adjacent base metal during the heating and cooling cycle of the welding process. Doing all welding on one side of a part will cause much more distortion than if the welds are alternated from one side to the other.

#### How is expansion and contraction used in our daily life?

Thermal expansion and contraction affect the volumes of liquids that are used every day. Cars provide a good example of this. Cold gasoline in a car’s gas tank expands in hot weather. Also, if a car engine is filled with cold liquid coolant, the coolant will warm up and expand when the car is running, and may overflow.

What is expansion process?

The Joule expansion (also called free expansion) is an irreversible process in thermodynamics in which a volume of gas is kept in one side of a thermally isolated container (via a small partition), with the other side of the container being evacuated.

How will you show that substance expand on heating and contract on cooling?

the ball through the ring. It does not pass through the ring . This clearly shows that on heating the diameter of the ball has increased i.e., the solid has expanded.