Changes

: [[Diffusion]] can only happen in a [[fluid]] which means (a [[liquid]] or a [[gas]] ) because the [[particle]]s can move past each other.

: In [[diffusion]] the particles [[particle]]s always spread from a high [[concentration]] (where there is are lots of the substance[[particle]]s, to a low [[concentration]] (where there is are less of the substance.: [[Diffusion]] stops when all [[substanceparticle]]s are spread out equally and there is no longer a [[Concentration Gradient|concentration gradient]]).

[[Diffusion]] is when [[substanceparticle]]s spread from a region of high [[concentration]] to a region of low [[concentration]] along a [[Concentration Gradient|concentration gradient]]. ===About Diffusion===: [[Diffusion]] can only happen in a [[fluid]] (a [[liquid]] or a [[gas]]) because the [[particle]]s can move past each other.: [[Diffusion]] cannot happen in a [[solid]] because the [[particle]]s are held in fixed positions.: In [[diffusion]] the [[particle]]s always follow the [[Concentration Gradient|concentration gradient]]spreading from a high [[concentration]] (where there is lots of the [[particle]]s), to a low [[concentration]] (where there are less of the [[particle]]s).: [[Diffusion]] stops when all [[substance]]s are spread out equally and there is no longer a [[Concentration Gradient|concentration gradient]]. {| class="wikitable"|-|[[File:Diffusion.png|center|600px]]|-| style="height:20px; width:600px; text-align:center;" |This [[diagram]] shows a high [[concentration]] of blue [[particle]]s on the left separated from the red [[particle]]s by a barrier. When the barrier is removed the blue [[particle]]s [[Diffusion|diffuse]] to the area of lower [[concentration]] on the right. [[Diffusion]] continues until all [[particle]]s are equally spread.|} {| class="wikitable"|-|[[File:Diffusion.gif|center]]|-| style="height:20px; width:600px; text-align:center;" |This animation shows a high [[concentration]] of red [[particle]]s initially at the top. When [[diffusion]] begins the red [[particle]]s spread to the area of lower [[concentration]] at the bottom. [[Diffusion]] continues until all [[particle]]s are equally spread.|}