The document describes the basics of chemical equations and changes. It defines key terms like reactants, products, compounds, elements, and formulas. It explains that a chemical equation uses symbols to represent the starting materials (reactants) and resulting materials (products) of a chemical reaction. Compounds are made of two or more elements chemically bonded together, while elements cannot be broken down further. Subscripts and numerical coefficients provide important information about the quantities of elements and compounds involved. Chemical changes rearrange elements to form new substances through reactions.

1. The Magic that Makes Chemistry
Happen
Pb(NO3)2 + 2KI 2KNO3 + PbI2

2. Pb(NO3)2 + 2KI 2KNO3 + PbI2
Chemical Equation
Chemical symbols showing what
reactants and products take part in a
chemical reaction.
Reactants are to the left of the arrow
Products are to the right of the arrow

3. Pb(NO3)2 + 2KI 2KNO3 + PbI2
 Compound
 Made of two or more elements chemically
combined. It can be broken down into simpler
parts by a chemical reaction.
 One compound is a molecule
 One molecule of water H2O
 One molecule of Lead Nitrate Pb(NO3)2

4. Pb(NO3)2 + 2KI 2KNO3 + PbI2
2 molecules of water would be…..2H2O
2 molecules of potassium iodide woud be..
2KI

5. Elements are symbolized by one or
two letters
 Pb(NO3)2 + 2KI 2KNO3 + PbI2
2K 2
K = Potassium
 N = Nitrogen
 O = Oxygen
 Pb = Lead
 I = Iodine
 Each time you see the symbol for an element, it
represents one atom of that element.

6. Pb(NO3)2 + 2KI 2KNO3 + PbI2
 Element
A substance that can NOT be broken down by
either physical or chemical means
 Elements make compounds
 An atom is the smallest piece of an element

7. All Elements can be found on the
Periodic Table of Elements
More on that later

8. When the letters that symbolize the
elements making up a compound
are written together they make a
formula
 H20 = the formula for water
 H202 = the formula for hydrogen peroxide
 CaCl2 = the formula for calcium chloride
 The formula represents one molecule of
the compound

9. Subscript numbers are small
numbers just to the right of the
letter of an element’s symbol
 H 2O
 The subscript number tells how many of
that element are in the molecule
 Ifno subscript number is present, then
there is one of that element

10. Full size numbers to the left of a
formula tell how many molecules of
a compound there are
 2KNO3
 This formula indicates 2 molecules of potassium
nitrate
 In each of the two molecules of potassium
nitrate there is:
 1 potassium (K)
 1 Nitrogen (N)
 3 Oxygen (O)
 How many atoms of each element are there in 2
molecules of potassium nitrate?????

11. CHEMICAL CHANGE
When a CHEMICAL CHANGE happens,
the elements are rearranged during a
chemical reaction and new compounds are
formed.
A brand new substance has been created

12. Homework!
 Brainpop – Chemical and Physical
Change

13. Now……………

14. States of
Matter

15. Can Matter Change State?
 Can it change from a solid to a liquid or a
liquid to a gas?
How?
Temperature or Pressure

16. http://www.harcourtschool.com/activity/states_of_
/

17. 0 degree C
-78.5 degree C
-196 degree C
-268 degree C

18. What are the Terms Given to Change of State?
L
I
Solid +
Q
Solid Energy U
I Melting
D
G
Evaporation
Liquid
Liquid + Energy
A
S
L
I
Gas
Gas - Energy
Q
U
I
Condensation
D
S
liquid
liquid - Energy
O
L
I
Freezing
D