physical state of a substance

Question 1

when is a substance solid?

Answer 1

at a temperature below its melting point

Question 2

when is a substance liquid?

Answer 2

at a temperature below its melting and boiling point

Question 3

when is a substance gas?

Answer 3

at a temperature above its boiling point

Question 4

difference between boiling and evaporation

Answer 4

boiling: attractive forces are broken throughout the liquid to produce bubbles of vapour
evaporation: some faster moving particles break away from the surface of the liquid

Question 5

what happens when there is a lower boiling point?

Answer 5

the forces of attraction are weaker causing the substance to evaporate faster

Question 6

what is diffusion?

Answer 6

the spreading of a substance from an area of high concentration to an area of low concentration as a result of the random movement of particles colliding with each other and bouncing in all directions until equilibrium is reached.