The States
What are the 3 states of matter?
Solid, Liquid and Gas
Freezing point.
What is a reversible change?
Changes that are physical in matter are reversible. This means that the changes can be changed back.
What is an irreversible change?
Changes that are
chemical in matter are
irreversible. This means
that once the change has
been made, it cannot be
changed back.
What is matter?
Matter is everything around us. Matter is anything that has mass and takes up space.
Explain what the atoms in a solid are like.
With a solid the atoms are
very tightly packed together.
This helps to give the object
the shape. The molecules
cannot move.
What is the term for when matter changes from a solid to a liquid.
Give an example of a reversible change.
Multiple answers accepted.
Give an example of an irreversible change.
when a bicycle or car begins to rust. We cannot change the rust back to the material the car was made from. The rust is an irreversible change.
A chemical change is caused by...
A chemical reaction. A new substance is formed and energy is either given off or absorbed.
Explain what the atoms in a liquid are like.
With a liquid the atoms are
not tightly packed together.
The atoms can move around.
The particles can move past
each other.
On a warm day... puddles will __________. (this is an example of liquid to gas)
Evaporate or vaporization
True or False: boiling an egg is a reversible change?
False. Once an egg is boiled it cannot be changed back into its original state.
True or False: having a camp fire is an example of a chemical change?
True:
Once the wood has been burned, it cannot be unburned. Instead, wood in the presence of heat and oxygen is transformed into fire.
When a chemical change happens, there are usually indicators... what are some of these?
Some examples of
indicators of chemical changes might be:
- a smell
- the production of gas
- a change of colour
- a build up (such as rust)
Explain what the atoms in gas are like.
With a gas the particles can move past one another. There is lots of free space between particles.
When condensation happens, which states are changing?
Gas to Liquid
What is a physical change?
A physical change does not change what the substance is. An example of this is taking a cup of water and placing it into the freezer. Solidifying the liquid that is water does not change what the water is – it is still water. It is just that the physical state of matter has been changed.
What is a chemical change?
With a chemical change there is a chemical reaction. A new substance is
formed and energy is either given off or absorbed.
What is the difference between a physical and chemical change?
A physical change is a change that is reversible. An example of this is if we changed a solid to a liquid. That liquid could be turned back into a solid. A chemical change is the result of a chemical reaction. With a chemical reaction a new substance is formed. A chemical change is not reversible. It is irreversible. An example of this is when we boil an egg. When the egg is being boiled, it can not be un-boiled.
Can all matter be changed from one state to another?
Yes.
Names for:
a) Solid to gas
b) Gas to solid
a) Sublimation
b) Deposition
When an ice cube melts and changes from a solid to a liquid, is it absorbing or releasing heat? Explain.
Absorbing heat.
As the ice cube is melting and changing from a solid to a liquid, the ice cube is absorbing heat. This absorption of heat allows for the ice cube to melt.
When matter changes from one state to another... it is either releasing ______ or absorbing _______.
When we release heat, we are getting rid of the heat in that object... name the state changes that fall into this category.
We release heat when we are changing a liquid to
a solid, gas to liquid or gas to solid.