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Difference between revisions of "Melting"

(Key Stage 4)
(Key Stage 4)
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: The [[temperature]] at which a [[substance]] '''melts''' is called its [[Melting Point|melting point]].
 
: The [[temperature]] at which a [[substance]] '''melts''' is called its [[Melting Point|melting point]].
 
: [[Melting]] is an [[endothermic]] process, which means it needs to [[Absorb (Physics)|absorb]] [[energy]] to take place.
 
: [[Melting]] is an [[endothermic]] process, which means it needs to [[Absorb (Physics)|absorb]] [[energy]] to take place.
 +
: [[Melting]] is a [[Physical Change|physical change]], which means it is [[Reversible Changes|reversible]] and does not produce new [[chemical]]s.
  
 
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Revision as of 10:08, 27 December 2018

Key Stage 2

Meaning

Melting is when a solid turns into a liquid.

Verb: To melt
Present Participle: Melting
When you heat a solid:
Melting.png
A solid will melt and become a liquid.

About Melting

Most solids can be melted to become a liquid.
Melting is a reversible process. When a solid melts you can always freeze it back into a solid.
You may have seen these solids melt
  • Ice
  • Wax
  • Chocolate
  • Butter

Examples

IceCubes.png
Candles.png
Some ice cubes melt to make water. Wax melts because of the flame.
ChocolateMelt.png
ButterMelt.png
Chocolate can melt in your mouth because your mouth is warm. You can melt butter in a frying pan.

Key Stage 3

Meaning

Melting is an endothermic process in which a solid turns into a liquid.

About Melting

Most solids can be melted to become a liquid.
Melting is a reversible process. When a solid melts you can always freeze it back into a solid.
A solid can be melted by heating it.
When you heat a solid:
ParticleModelMelting.png
The particles in the solid vibrate faster until they vibrate fast enough that they break the bonds holding them in fixed positions. The particles become able to move past each other but are still touching which makes the state a liquid.

Key Stage 4

Meaning

Melting is an endothermic physical change in which a solid turns into a liquid.

About Melting

Melting happens when the particles in a solid break bonds holding them in fixed positions as they gain potential energy.
The temperature at which a substance melts is called its melting point.
Melting is an endothermic process, which means it needs to absorb energy to take place.
Melting is a physical change, which means it is reversible and does not produce new chemicals.
MeltingGraph.png
As a solid is heated the internal energy increases. As the solid melts the temperature of the substance stays the same.