1. Section 2 Properties of Matter
Chapter 15 Matter
Section 2 Properties of Matter

2. Physical Change A change in size, shape, or state of matter
The identity of the substance does not change
Example:
Heating iron (it will change color but its composition stays the same)

3. Chemical Property
Characteristic of a substance that tells whether it can undergo a chemical change
Example:
Flammability

4. Chemical Change Change from one substance to another Example:
Dropping antacid tablet into water
Rusting of iron

5. Clues of Chemical Change
Heat
Cooling
Formation of bubbles, or formation of solid

6. Weathering Some weathering is physical and some is chemical
Physical: Large rocks breaking
Chemical: Break down of limestone

7. Chapter 17 Properties of Atoms and the Periodic Table
Section 1

8. Atom
Smallest piece of matter that still has the properties of the element it composes
“Building Block of Matter”

9. Parts of Atom Nucleus Found in the center of the atom
Contains protons (+) and neutrons (no charge)
Electron Cloud
Surrounds the nucleus
Contains electrons (-)

10. Atomic Number Number of protons in an atom Example: Carbon – 6
Oxygen - 8

11. Mass Number Number of protons + number of neutrons
Find # of neutrons in carbon:
mass number = # of protons (atomic #) + # neutrons
12 = 6 + # neutrons
# neutrons = 6

12. Isotopes
Atoms of the same element with different # of neutrons

13. Chapter 17 Properties of Atoms and the Periodic Table
Section 3

14. Organizing the Elements
Dmitri Mendeleev first organized the elements by increasing atomic #
Today this arrangement is called a periodic table
The elements are arranged by increasing atomic # and by changes in physical and chemical properties

15. Periodic Table of Elements

16. Periodic Table Groups- the vertical columns in the table 18 groups
Elements are arranged in groups according to similar properties

17. Electron Cloud In neutral atoms the # of protons = # of electrons
There are 7 energy levels in the electron cloud

18. Electron Cloud
p. 520 Fig. 10
*This shows the maximum # of electrons each energy level can hold.
A complete and stable energy level will contain 8 electrons

19. Outer Electrons Outermost electrons are also called valence electrons
*Group 1 elements have 1 valence electron
*Group 2 elements have 2 valence electrons
*Group 18 elements have 8 valence electrons

20. Electron Dot Diagram Created by G.N. Lewis
This uses the symbol of the element and dots to represent the outer electrons

21. Periodic Table Vertical Columns are called groups
Horizontal Rows are called periods

22. Periods
In periods on the periodic table, the atomic # will increase by one as you go from left to right

23. Chapter 19 Elements and Their Properties
Section 1 Metals

24. Metals
Good conductors of heat and electricity and solids at room temperature
*Except Mercury
Find the metals on the periodic table

25. Properties of Metals Malleable
- they can be hammered or rolled into sheets
Ductile
- They can be drawn into wires

26. Alkali Metals
Just like other metals, except they are softer and extremely reactive
Do not exist as free elements in nature
Find them on the periodic table

27. Alkaline Earth Metals
These also do not exist as free elements in nature due to their reactivity
Find them on the periodic table

28. Transition Elements Found in Groups 3-12
Called transition elements b/c they are considered to be in transition between Groups 1 & 2 and Groups
Find them on the periodic table

29. Lanthanides
Elements with atomic #’s 58-71

30. Actinides
Elements with atomic #’s