# Liquids and Gases

## 5.16 use the relationship between the pressure and Kelvin temperature of a fixed mass of gas at constant volume

5.16 use the relationship between the pressure and Kelvin temperature of a fixed mass of gas at constant volume p1 / T1 = p2 / T2

## 5.17 use the relationship between the pressure and volume of a fixed mass of gas at constant temperature

5.17 use the relationship between the pressure and volume of a fixed mass of gas at constant temperature p1V1 = p2T2

## 5.10 understand that molecules in a gas have a random motion and that they exert a force and hence a pressure on the walls of the container

5.10 understand that molecules in a gas have a random motion and that they exert a force and hence a pressure on the walls of the container Gases are made up of particles that are moving. The particles in gases are spread out and constantly moving in random. They hit...

## 5.13 understand that an increase in temperature results in an increase in the average speed of gas molecules

5.13 understand that an increase in temperature results in an increase in the average speed of gas molecules If we heat gas molecules, they gain more kinetic energy. As they do so, they begin to move faster and the average speed of the molecules increases.

## 5.14 understand that the Kelvin temperature of the gas is proportional to the average kinetic energy of its molecules

5.14 understand that the Kelvin temperature of the gas is proportional to the average kinetic energy of its molecules Temperature in Kelvin is directly proportional to the average kinetic energy of molecules. If we increase the temperature, kinetic energy as well as...

## 5.15 describe the qualitative relationship between pressure and Kelvin temperature for a gas in a sealed container

5.15 describe the qualitative relationship between pressure and Kelvin temperature for a gas in a sealed container The number of gas particles and the space, or volume, they occupy remain constant. When we heat the gas the particles continue to move randomly, bu with...

## 5.1 use the following units: degrees Celsius (oC), Kelvin (K), joule (J), kilogram/metre3 (kg/m3), kilogram/metre3 (kg/m3), metre (m), metre2 (m2 ), metre3 (m3), metre/second (m/s), metre/second2 (m/s2 ), newton (N), Pascal (Pa). Unit of temperature: degrees Celsius (oC) Unit of temperature: Kelvin (K) Unit of mass: kilogram/metre3 (kg/m3) Unit of density: kilogram/metre3 (kg/m3) Unit of distance: metre (m) Unit of Area: metre2 (m2) Unit of Volume: metre3 (m3) Unit of Speed: metre/second (m/s) Unit of Acceleration: metre/second2 (m/s2) Unit of force: newton (N) Unit of Pressure: Pascal (Pa)

5.1 use the following units: degrees Celsius (oC), Kelvin (K), joule (J), kilogram/metre3 (kg/m3), kilogram/metre3 (kg/m3), metre (m), metre2 (m2 ), metre3 (m3), metre/second (m/s), metre/second2 (m/s2 ), newton (N), Pascal (Pa). Unit of temperature: degrees Celsius...

## 5.2 know and use the relationship between density, mass and volume

5.2 know and use the relationship between density, mass and volume density=mass/volume p=m/V

## 5.3 describe experiments to determine density using direct measurements of mass and volume

5.3 describe experiments to determine density using direct measurements of mass and volume Suppose a rectangular block have a volume of 50 m3 and mass of 200kg. Its density will be 200/50 kg/m3, i.e. 4kg/m3.

## 5.4 know and use the relationship between pressure, force and area

5.4 know and use the relationship between pressure, force and area ρ=force/area p=F/A

## 5.5 understand that the pressure at a point in a gas or liquid which is at rest acts equally in all directions

5.5 understand that the pressure at a point in a gas or liquid which is at rest acts equally in all directions Pressure in liquids and gases act equally in all directions, as long as the liquid or gas are not moving.

## 5.6 know and use the relationship for pressure difference

5.6 know and use the relationship for pressure difference pressure difference = height × density × g p = h × ρ × g

## 5.7 understand the changes that occur when a solid melts to form a liquid, and when a liquid evaporates or boils to form a gas

5.7 understand the changes that occur when a solid melts to form a liquid, and when a liquid evaporates or boils to form a gas When a solid is heated, the molecules starts vibrating. At a time they lose their attraction force and move slowly. This time they reach the...

## 5.8 describe the arrangement and motion of particles in solids, liquids and gases

5.8 describe the arrangement and motion of particles in solids, liquids and gases Features Solid Liquid Gas Arrangement Regular Irregular Random Movement Cannot move, vibrate only Particles can move throughout the liquid slight past each other The particles have the...