CHANGES IN MATTER
Physical changes – Chemical changes

Physical and chemical changes
Differences and how to identify them.
Source | Homeschool Pop

CHANGES IN MATTER
Physical changes

physicalchange_wordle

In a physical change, the matter doesn’t change.
No new substances are created.
The matter just changes shape or state.

PhysicalChangesMix

Commercial | Evian Water Boy
Music | “We Will Rock You” (1977) Queen
Source | Saatchi & Saatchi New Creators Showcase

Physical changes happen to water in the water cycle.
Water changes shape and state, but not its substance.
In the water cycle, water stays as water.

IceMelting1_460

The ice melting is a physical change.
Water changes shape and state, but not its substance.

ClayHandsOn1_460

Modeling clay is a physical change.
The clay changes its shape, but not its substance.

AluminumFoilCutHalf

Cutting strips of aluminum foil is a physical change.
The aluminum foil changes its shape, but not its substance.

Some physical changes are reversible.
They are temporary changes or can be reversed.

Some physical changes are irreversible.
They are permanent changes.

If you freeze water into an ice cube,
you can melt it into the water again.
This is a reversible change.

You can freeze juice (liquid) to make ice lollies.
But, they can melt and become liquid again.
This is a reversible change.

If we cut a piece of paper,
we cannot return it to its original form.
This is an irreversible change.

If we break a glass,
we cannot return it to its original form.
This is an irreversible change.

CHANGES IN MATTER
Chemical changes

In a chemical change, the matter change.
In a chemical change, a new substance is produced.

chemicalchange_wordle

A chemical change happens when
we burn a substance
or expose a substance to air.

ChemicalChangesMix

CHEMICAL CHANGES
combustion – fermentation
oxidation – putrefaction

Combustion, fermentation, oxidation, and putrefaction
are chemical changes.

CHEMICAL CHANGE
Combustion

MatchLit_460

Combustion is a chemical reaction.
It’s a reaction between a fuel and the oxygen.

Lit a match is a chemical change.
Combustion produces new substances:
a flame, smoke, ash, carbon dioxide, and other gases.

CHEMICAL CHANGE
Fermentation

Fermentation is a chemical reaction.
It’s caused by organisms like bacteria and fungi.
They produce new substances.

Yeast is a fungus that ferments bread dough.
It produces carbon dioxide which makes the dough rise.

Some food is fermented by bacteria and fungi:
beer, wine, bread, cheese, yogurt, olives, and pickles.

CHEMICAL CHANGE
Oxidation

NailRusting1_460

Rusting is a chemical change.
This process is called oxidation.
Oxidation is a chemical reaction.

Iron and steel are metals. They can rust.
Rusting is the corrosion of iron or steel.
They rust when they react with oxygen or water.

CHEMICAL CHANGE
Putrefaction

apple_browning

Putrefaction is a chemical change.
It’s a chemical reaction.

When organic matter decomposes, putrefaction occurs.

It happens to fresh fruit when you leave it for long time.
The food softens, changes colour and smells bad.

PEDROLEÓN.