Changes In State

Question 1

why do changes in state occur?

Answer 1

a change in state is due to the particles absorbing or losing energy

Question 2

when a substance is _____, it ______ energy. When it is _______, it _______ energy.

Answer 2

heated, absorbed

cooled, loses

Question 3

describe the process of state change from solid to liquid.

Answer 3

1) when a solid is heated, the particles gain energy.
2) this makes the particles vibrate more, which weakens the forces of attraction. this makes the solid expand.
3) at a certain temperature, the particles have enough energy to break free from their forces of attraction holding them in position. this is called melting.

Question 4

describe the process of state change from liquid to gas

Answer 4

1) when a liquid is heated, the particles gain kinetic energy.
2) this increase in energy makes the particles move faster, which weakens and begins to break their bonds.
3) at a certain temperature, the particles have enough energy to break their bonds. this called evaporation.

Question 5

how to structure an answer on graphs? (SKP PMES SKT)

Answer 5

AB: what state is the substance in? does it lose or gain kinetic energy? do the particles move closer together or further apart? (SKP)

BC: what process is occurring? what does the substance become a mixture of? do particles lose or gain energy? what structure do they begin to form?

(PMES)

CD: what state is the substance in? do they lose or gain kinetic energy? does the temperature increase or decrease?

(SKT)