2,903
edits
Changes
no edit summary
: When a [[solid]] [[subliming|sublimates]] [[energy]] is needed to break the [[bond]]s holding the [[particle]]s in fixed positions and keeping the [[particle]]s together.
*[[Freezing]], [[Condensing]] and [[Depositing]] are [[exothermic]] changes because it releases [[energy]] when it happens. The [[material]] has less [[after]] it has happened.
: When a [[gas]] [[condensing|condenses]] [[energy]] is released as [[bond]]s form between adjacent [[molecule]]s to hold them together.
: When a [[liquid]] [[freezing|freezes]] [[energy]] is released as [[bond]]s form between adjacent [[molecule]]s to keep them in fixed positions.
==Key Stage 4==
===Meaning===
A '''state change''' is a [[Physical Change|physical change]] in which a [[substance]] turns from one [[State of Matter|state of matter]] into to another.
===About State Changes===
: '''State changes''' happens are [[reversible]] because after a '''state change''' the [[material]] can be returned to its original form with the same [[property|properties]] as it started with.: '''State changes''' happen when a [[substance]] gains enough [[energy]] to break the [[bond]]s holding [[particle]]s together or loses enough [[energy]] for [[bond]]s to form between [[particle]]s.: When the [[bond]]s between [[particle]]s in a [[solid]] or a [[liquid]] are broken the [[particle]]s gain [[Potential Energy|potential energy]]. This is an [[endothermic]] process because it needs [[energy]].: When [[bond]]s are formed between [[particle]]s in a [[gas]] or a [[liquid]] the [[particle]]s lose [[Potential Energy|potential energy]]. This is an [[exothermic]] process because [[energy]] is given off. ====Edexcel==== :[https://www.amazon.co.uk/gp/product/1292120215/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120215&linkCode=as2&tag=nrjc-21&linkId=8f96ddb76196848bafdb124354e4cf77 ''State changes, page 3, GCSE Chemistry, Pearson, Edexcel '']