28. Heating and changes

 

 

YesNo, all changes caused by heating are not chemical decomposition changesnon-recoverable changesreversible changespermanent changes. Some heating changes are reversible, such as burning of ice into vapourmelting of icewater changing into smokefreezing of steam into gas and boiling of watersteam turning into solid instantly without coolingwater turning into icewater becoming ash, because they can be reversed on cooling. However, some changes are temporary changesFreezing and melting changesirreversible changesphysical state changes only, such as Food turning back into raw ingredientsPaper changing into waterburning of paperPaper freezing into ice and cooking reversing into raw egg automaticallyburning producing only liquid waterfood turning into its original form after coolingcooking of food, where new substances are formed. In irreversible changes, the original substance cannot be obtained back. Therefore, heating can cause both reversible and irreversible changes.