internal energy

Question 1

what 2 types of energy to particles in a system have?

Answer 1

kinetic and potential

Question 2

what does internal energy mean?

Answer 2

energy (potential and kinetic) stored in a system by all the particles

Question 3

if we heat a solid/liquid, what happens to its internal energy?

Answer 3

when a solid/liquid is heated, internal energy increases

Question 4

if we cool a gas/liquid, what happens to its internal energy?

Answer 4

when a gas/liquid is cooled, internal energy decreases

Question 5

what is sublimination?

Answer 5

where a solid can directly turn into a gas

Question 6

when a change of state takes place, mass is conserved, what is meant by this?

Answer 6

no particles are added or taken away

Question 7

changes of state are physical changes and not chemical changes, what is meant by this?

Answer 7

if we reverse the change, material recovers its original properties

Question 8

what is evaporation?

Answer 8

when a liquid turns to a gas but only on the surface of the liquid