internal energy and brownian motion

Question 1

absolute zero

Answer 1

the temperature at which a substance has minimum internal energy

Question 2

thermal equilibrium

Answer 2

objects in contact with each other at the same temperature are in thermal equilibrium, this means there is no net heat flow between them

Question 3

kinetic model of matter

Answer 3

made up of very small particles which are in constant motion. Model allows us to explain the properties of matter and changes of phase in terms of the arrangement of the particles, the motion of the particles and the attractive forces between them

Question 4

solids

Answer 4

particles are close together and vibrate about there individual fixed position
held together by strong forces of attraction
high density and a definite shape

Question 5

liquid

Answer 5

cannot move as much but they can slide past each other
forces of attraction are weaker than in solids
Lower density than solids and can flow and be poured

Question 6

gases

Answer 6

free to move around very quickly and in random directions

very weak forces of attraction between particles due to high separation between them

Question 7

internal energy

Answer 7

sum of the randomly distributed kinetic and potential energies of all the atoms and molecules within a system

Question 8

internal energy change during change of phase

Answer 8

kinetic energy does not change because there is no temperature change. however potential energy can change eg energy supplied to block of ice by heating wall turn it into water by overcoming intermolecular forces