Tag: the particle theory

Cycle tube when filled with the air it swells up because of the pressure exerted by the particles of the air present in the tube. The particles of air collide with each other and exert pressure on the walls of the tube.

The unit of the pressure is $pascal$. $N/m^2$, and $76\ cm\ of\ Hg$.

The atmospheric pressure changes throughout the atmosphere.
Example: As we go up in the air, the atmospheric decreases as the density of the air decreases. 

The atmospheric pressure can be given as $1.013\times 10^{5}\ pascals$ or $1.013\times10^{5}\ N/m^2$.

In 1643 Torricelli made an instrument for measuring atmospheric pressure. This device is called a barometer. This barometer can be either mercuric or aneroid barometer. 

In the human body, the pressure exerted by the cells in our body is equal to the atmospheric pressure. Hence we do not get shrunk.

The rate of diffusion of liquids is higher than that of solids. This is due to the fact that in the liquid state, particles move freely and have greater space between each other as compared to particles in the solid state.

Viscosity is a measure of how much a liquid resists flowing freely. Viscosity can usually be reduced by heating the liquid. When heated, the particles of the liquid move faster, allowing the liquid to flow more easily.

Only two elements are liquid at standard conditions for temperature and pressure i.e. mercury and bromine. 

Volatile liquids have low boiling point. As a result, they evaporate very easily at room temperature. Because of their low boiling points, volatile liquids convert to the gas phase at a lower temperature and the gas molecules can diffuse faster than the molecules of a non-volatile liquid.