Solids, liquids and gases (topic 5)

Question 1

Absolute zero

Answer 1

lowest possible temperature. at this temperature the particles have no kinetic energy and so are completely stationary

Question 2

Chemical changes

Answer 2

changes to the chemical structure of a substance

Question 3

Condensation

Answer 3

changing from vapour state to a liquid state when a substance is cooled

Question 4

Density

Answer 4

mass per unit volume of an object

Question 5

Evaporation

Answer 5

changing from a liquid to a vapour state when a substance is heated

Question 6

Freezing

Answer 6

changing from a liquid state to a solid state when a substance is cooled

Question 7

Gas temperature

Answer 7

absolute temperature of a gas is directly proportional to the average kinetic energy of its molecules

Question 8

Internal energy

Answer 8

energy stored by the atoms and molecules that make up a system. its equal to the sum of the total kinetic and potential energies of the particles in the system

Question 9

Kelvin

Answer 9

unit of temperature 0K is equal to -273 degrees celsius

Question 10

Melting

Answer 10

changing from solid to liquid state when a substance is heated

Question 11

Pascals

Answer 11

unit of pressure equal to a force of one Newton

Question 12

Physical changes

Answer 12

changes to the physical properties of a substance which can be reversed.

Question 13

Pressure in a liquid column

Answer 13

equal to the product to the height of the column the density of the liquid and the gravitational field strength

Question 14

Pressure of a gas

Answer 14

perpendicular force per unit area acting on the surfaces of a container as a result of the gas particles colliding with it

Question 15

Pressure

Answer 15

force acting perpendicular to a surface per unit area

Question 16

Pressure - volume relationship

Answer 16

when at a constant temperature the volume of a fixed quantity of gas is inversely proportional to its pressure

Question 17

Pressure - temperature relationship

Answer 17

when at a constant volume the pressure of a fixed quantity of gas is directly proportional to its absolute temperate

Question 18

Temperature

Answer 18

measure of the average kinetic energy of the particles in a substance.