C1 Internal Energy - States of matter, Def, First law of thermodynamics

States of matter
-Solid are the most dense and their particles can vibrate but are held strongly by intermolecular forces.
-Particles in liquids are free to move but are still restricted by their intermolecular forces
-Gases are the least dense and particles move completely freely while experiencing intermolecular forces only during collisions.

Internal energy(U)
-Particles have kinetic energy due to their motion and potential energy due to intermolecular forces
{Def:-The internal energy of an object is the sum of the random distribution of kinetic and potential energy of its particles.
-Internal energy of a substance is more affected by K.E of particles rather than P.E
-Internal energy of states of matter-->gas>liquid>solid
-What will happen to particles if you supply heat?
-The internal energy of the material increases
-What will happen if you compress a gas using a piston?
-Compressing the gas by applying a force causes the piston to move, which makes the piston do work on the gas
-According to the conservation of energy, this work done on the gas transfers E to the gas causing the U to ^

First law of thermodynamics
-Change in internal energy of a system is equal to the total E transferred due to work done and heating
/\U=Q or /\U=Q+W if on the system by the system /\U=Internal E Q=heat supplied W=Work done
The change of internal energy is equal to the difference of heat supplied and work done by system