Unit 5 : Physical and Chemical Changes of Matter -

1. Matter:

Everything that exists.
Made up of atoms.

2. Atoms:

Center: Nucleus (protons & neutrons)
Outside: Electrons

3. Molecule:

When two or more atoms join.

Example: Water (H₂O)

Two Hydrogen atoms + One Oxygen atom

States of Matter

State	Particle Arrangement	Particle Movement	Volume/Shape
Solid	Atoms are tightly packed.	Vibrate; cannot move freely.	Has a definite shape.
Liquid	Atoms are close together, but not tightly packed.	Can easily move or slide past each other.	Takes the shape of the container.
Gas	Atoms are not close.	Move freely at high speed.	Takes the shape of the container.

Physical Change and Effect of Heat on Matter

5) Physical Change

A physical change occurs when matter changes how it looks (its size, shape, or state).

No new substance is made.
The change is temporary.
It can be reversed or undone.

6) Effect of Heat on Matter

Heat can change matter from one form (state) to another.

Process	Change	Example
Melting	Solid Liquid	Ice Water
Freezing	Liquid Solid	Water Ice
Condensation	Gas Liquid	Steam Water
Evaporation	Liquid Gas

Adding heat or taking away heat changes the temperature, which changes the state of matter.

7) Melting

Melting is the change from Solid Liquid.

Solid particles have very little energy; they do not move around.
Liquid particles have more energy than solids and move around.
To turn solid liquid, you must add more energy (heat).
Melting temperature (melting point) is different for different solids.
- Ice melting point
- Gold melting point more than

8) Boiling

Boiling is the change from Liquid Gas by heating.

Heat is given to the liquid.
The particles (atoms) move further away from each other.

Here is the text-based infographic based on the sixth and seventh images you provided:

9) Freezing

Freezing is the change from Liquid Solid by taking away energy (heat).

In freezing:
- Particles stop moving.
- Particles become closer and closer.
All liquids have a freezing point, which is measured by temperature.
When the temperature falls below the freezing point, the liquid becomes solid.
- Water freezes or .

10) Condensation

Condensation occurs when a gas is cooled so much it becomes liquid.

Chemical Change and Mixtures & Solutions

Chemical Change

A chemical change is when a substance changes and a completely new material (substance) is formed.

The change is irreversible (permanent).
The new substance cannot easily turn back to the original.

Examples:

Cooking an egg: Cannot turn a boiled/fried egg back to raw.
Baking a cake.
Rusting.

Change Type	What Happens	Can Be Reversed?
Physical	Only shape/state change; No new material formed.	Yes
Chemical	New material forms.	No

11) Mixtures & Solutions

Mixtures

Made by combining two or more substances (materials).
Materials in a mixture keep their own properties (don’t change).
Materials can be separated (e.g., Salt & Sand).

Solutions

A specific type of mixture where Material 1 (Liquid) + Material 2 (Solid) are combined. (e.g., Sugar in water).
Materials in a solution do not separate naturally.

Type	Description
Concentrated (Strong)	Lots of dissolved material.
Diluted (Weak)	Small amount of dissolved material.

Making things dissolve faster:

Increasing temperature.
Stirring.
Breaking solid into smaller pieces.

Getting solid back from a solution:

Boil the solution; the water will evaporate, leaving the solid.

Q1. What are atoms made of?

a) Only protons & electrons
b) Nucleus (protons & neutrons) and outside electrons
c) Molecules & electrons
d) Two or more molecules

Q2. What is a molecule?

a) Smallest unit of matter
b) Single atom
c) two or more atoms join up
d) electron orbiting nucleus

Q3. In which state of matter are atoms tightly packed, vibrating, and unable to move or slide past each other?

a) Liquid
b) Gas
c) Solid
d) Plasma

Q4. What is the arrangement & movement of atoms in Gas?

a) tightly packed, not vibrating
b) close together, can easily move or slide past each other
c) Not close, move freely at high speed
d) Not tightly packed, definite shape

Q5. What energy (more or less) do solid particles generally have compared to liquids

a) More energy
b) Less energy
c) Very little energy
d) kinetic energy

Q6. Which key characteristic of physical change is important?

a) new substance is made
b) usually irreversible
c) matter change: how it look (Size, shape)
d) cannot be reversed

Q7. What is the process of liquid turning into solid by taking away energy (heat)

a) melting
b) boiling
c) freezing
d) condensation

Q8. Process of liquid changes to gas

a) chemical change
b) freezing
c) Condensation
d) Evaporation.

Q9. What is defining (important) feature of chemical change?

a) only size & shape of substance change
b) change is temporary
c) new material is formed
d) change is reversed.

Q10. Example of irreversible change

a) melting of ice
b) evaporating water to steam
c) cooking egg
d) freezing water to ice

Q11. Which change is defined by “New material form” and “Cannot be reversed”

a) physical change
b) change of state
c) chemical change

Q12. At what temperature does pure ice melt?

a) 32∘F
b) 0∘C
c) more than 100
d) when temperature fall below freezing point

Q13. In mixture, how do properties of original material change?

a) completly change and form new material.
b) keep own properties
c) dissolve permanently
d) become more concentrated

Q14. Which of the following is a way to make solid dissolve faster in liquid

a) decreasing temperature
b) solid settle
c) Break solid in small pieces
d) Take away heat

Q15. To get a dissolved solid back from solution, what process can be used.

a) Stirring
b) Boiling
c) Add more dissolved material
d) Lower temperature

Q1. b
Q2. c
Q3. c
Q4. c
Q5. c
Q6. c
Q7. d
Q8. d
Q9. b
Q10. b
Q11. c
Q13. c
Q14. c
Q15. c