1. Acids and bases
Acids and bases and be very useful , but can also be very dangerous
It is very important to always read the chemical labels when dealing with acids and bases

2. How do we tell? How do we tell if a substance is an acid or a base?
Use an indicator such as litmus paper, red cabbage juice, grape juice, etc...
Indicators react in the presence of acidic or basic substances.

3. Litmus paper Acid substance : Red litmus -> stays red
Blue litmus -> turns red
Basic substance : Red litmus -> turns blue
Blue litmus -> stays blue
Neutral substance: Red litmus -> stays red

4. pH scale
This scale classifies substance according to their acidity or alkalinity
The scale ranges from 0 -14
Acid <7
Base >7
Neutral =7

5. Change of State & Particle Theory
Solid (close particles)
+heat
*melting point
= liquid (particles are farther apart)
+ heat
*boiling point
= gas (particles far apart)

6. Physical vs. Chemical transformation
In a physical change you only change the state of the substance.
In a chemical change your substance changes its chemical properties and becomes something new
Signs of a chemical change:
1) gas is formed
2) A residue is formed
3) heat or light is produced
4) A colour change occurs

7. Rule of thumb on physical vs. Chemical changes
If it can go back to its original form  physical change
If it can’t revert to its original form  chemical change

8. Law of conservation of mass
***The mass substances that undergo a transformation is always equal to the mass of the resulting substances

9. In class work P.193 (# 9-12) P.196 (# 1-4) P. 197(# 1-3)
List whether the following are physical/chemical
changes.
Lake freezing
Crushing an ice cube
Burning toast
Melting a gold bar
Cutting a loaf of bread
A tree decomposing