1. Atom The smallest unit of matter This is a carbon atom.
How small is small?
1 Atom of Helium
Diameter = 50 picometers (1/1,000,000,000,000)
Mass = 1.67 x kilograms
Atoms most common in living organisms:
carbon
nitrogen
hydrogen
oxygen

2. Subatomic Particles: The parts of the atom
Electron cloud:
Space around the nucleus which has “levels”
Location of …….
Nucleus: Center of the atom
Location of…….
Protons
Neutrons
electrons
1st level: 2 electrons
2nd level: 8 electrons
3rd level: 8 electrons

3. Particle Charges Protons have a positive charge (+)
Neutrons have no charge (0)
Electrons have a negative charge (-)

4. Atomic Number The number of protons an atom has.
This number never changes!
It is also the number of electrons a neutral atom contains

5. Atomic Mass Number of protons and neutrons in the nucleus
Atomic Mass = Protons + Neutrons
Electrons are too small to contribute much to the mass

6. Drawing Atoms Draw the Nucleus
Add protons (+) and neutrons (o) into the nucleus
Draw at least one electron level.
Add electrons remembering the number each level can hold; you may need to add more electron levels
1st: 2 electrons
2nd: 8 electrons
3rd: 8 electrons

7. Atomic Structure & The Periodic Table

8. Periodic Table of Elements
A chart of all elements known to man. Arranged in rows and columns. In order of atomic number.

9. Periodic Table of Elements
Element – a substance made of only one kind of atom
Example: Carbon Atoms can combine to make elemental carbon in the form of coal or diamonds.
Chemical Symbols: Letters that represent the elements
C-carbon
H- hydrogen
N- Nitrogen
O-Oxygen
P- Phosphorous

10. Shows information about each element
Atomic Number
Average Atomic Mass
Number will be shown as a decimal. Why?
Average of all the isotopes of that element in nature
The actual Atomic Mass is not on the table- just an average

11. Mass Number always a whole number NOT on the Periodic Table!
mass # = protons + neutrons
always a whole number
NOT on the Periodic Table!
Neutron +
Electrons
Nucleus
Proton
Nucleus
Carbon-12
Neutrons 6
Protons 6
Electrons 6

12. Isotopes of Carbon Neutron + Electrons Nucleus Nucleus Proton Proton
Neutrons 6
Protons 6
Electrons 6
Electrons
Carbon-14
Neutrons 8
Protons 6
Electrons 6
Nucleus

14. Chemical Compounds
Substances made from 2 or more elements in defined proportions are called compounds
Formed by chemical bonds
Described by a chemical formula
H2O Hydrogen, 1 Oxygen
NaCl Sodium, 1 Chlorine
Mg(OH) Magnesium, 2 Oxygen, 2 Hydrogen

15. Chemical Bonding
Atoms interact with each other to form chemical compounds
Only the outermost ELECTRONS of the atoms are involved – AKA: Valence Electrons

16. Thursday Covalent Bonding Video
If you want more practice before your quiz tomorrow…
Bonus Opportunity!
Water Fact Sheet
CW/HW: Read and Notes 2-2 (Due Friday)

17. Ban Dihydrogen Monoxide Bonus
Read brochure
Type a paragraph explaining what this substance really is and how you know.
Why are the claims in the brochure true, but impossible? Explain why we can’t ban it!

18. Examples:

19. Stability
An atom is considered stable when its outermost energy level is “filled” with electrons
To achieve stability, atoms will gain, lose or share electrons

20. Ionic Bonds
Bond where electrons are transferred from one atom to another (gain or lose)
Ions (charged atoms) are held together by their charges.
Example: Na+ Cl-

21. Animations ionic bonding animation

22. Bond in which 2 atoms share electrons
Covalent Bonding
Bond in which 2 atoms share electrons
Atoms can share:
2 electrons (single bond)
4 electrons (double bond)
6 electrons (triple bond)
Examples H2O or CO2

23. How to show a covalent bond
1st draw a dot diagram for each element in the compound
Use dot diagrams to show sharing of valence electrons between atoms

24. Chapter 1 Test Summary 3rd Period 4th Period 5th Period Average 83%
81%
85%
# of A’s 4
# of B’s 14 10 17
# of C’s 7 5 2
# of D’s 3 1
#of F’s
Highest Score
91%
93%
94%
Lowest Score
70%
68%
69%