19,879
edits
Changes
→Key Stage 4
: The [[particle]]s in a [[material]] have [[Kinetic Energy Store|kinetic energy]], because they move, and several types of [[Potential Energy|potential energy]] because there are [[force]]s between [[adjacent]] [[particle]]s.
: [[Force]]s of [[attraction]], including [[Chemical Bond|chemical bonds]], pull [[particle]]s together. The further apart the [[particle]]s the more [[Potential Energy|potential energy]] they poses. As a result the [[gas]]eous [[State of Matter|state]] of a [[substance]] has more [[Potential Energy|potential energy]] than the [[liquid]] [[State of Matter|state]] of that [[substance]], even if the [[temperature]] of both is the same because the [[particle]]s are spread apart in a [[gas]] and close together in a [[liquid]].
: Increasing the '''internal energy''' of a [[substance]] by [[heating]] does not always increase its [[temperature]]. When a [[substance]] [[State Change|changes state]] the '''internal energy''' changes but the [[Thermal Energy Store|thermal energy]] does not, so it remains at a constant [[temperature]].
{| class="wikitable"
|[[File:MeltingGraph.png|center|300px]]
|[[File:BoilingGraph.png|center|300px]]
|-
| style="height:20px; width:300px; text-align:left;" |As a [[solid]] is [[heated]] the [[Internal Energy|internal energy]] increases. As the [[solid]] '''melts''' the [[temperature]] of the [[substance]] stays the same but the [[Potential Energy|potential energy]] of the [[particle]]s continues to increase.
| style="height:20px; width:300px; text-align:left;" |As a [[liquid]] is [[heated]] the [[Internal Energy|internal energy]] increases. As the [[liquid]] '''boils''' the [[temperature]] of the [[substance]] stays the same but the [[Potential Energy|potential energy]] of the [[particle]]s continues to increase.
|}
===Equation===
'' '''Internal Energy''' = All [[Kinetic Energy Store|kinetic energies]] + All [[Potential Energy|potential energies]]''