1. Structure of the Atom or “Let’s Get up and Atom”
Chemical Symbols
Nucleus/ clouds
Subatomic Particles
Atomic Terms

2. Metal that forms bright blue solid compounds.
Chemical Symbols
Capitals matter!
Element symbols contain ONE capital letter followed by lowercase letter(s) if necessary.
Metal that forms bright blue solid compounds.
Co vs. CO
Poisonous gas.

3. Subatomic Particles in a neutral atom Most of the atom’s mass.
NUCLEUS
ELECTRONS
in a neutral atom
PROTONS
NEUTRONS
NEGATIVE CHARGE
POSITIVE CHARGE
NEUTRAL CHARGE
Most of the atom’s mass.
Atomic Number
equals the # of...

4. Subatomic Particles
Quarks
6 types He
3 quarks = 1 proton or 1 neutron

6. II. Electron Clouds (shells)
Contain electrons (-)
Orbital
Energy Levels
Bohr Model Diagrams

7. Orbital Region where there is 90% probability of finding an electron.
Can’t pinpoint the location of an electron.
Density of dots represents degree of probability.

8. Orbitals have different shapes.

9. Energy Levels Electrons can only exist at certain energy levels.
Low energy levels are close to the nucleus.
Each energy level (n) can hold 2n2 electrons.

10. Bohr Model Diagrams
Simplified energy levels using Bohr’s idea of circular orbits.
Can replace with: 3p 4n
Lithium
Atomic #: 3
Mass:
# of p: 3
# of e: 3
# of n: 4 e- e- p n
Maximum e-
Level 1 2e-
Level 2 8e-
Level 3 18e-
Level 4 32e- e-

11. Bohr Model Activity Choose a number between 1 & 18.
Find your element by the atomic number you picked.
Draw a Bohr Model diagram for your element on your marker board.
Round off the mass listed on the table and subtract the atomic # to find the # of neutrons.
Abbreviate the # of ‘p’ and ‘n’ in the nucleus.
Have a partner check your drawing.
Repeat with a new element.

12. Atomic Number (Z) Mass Number (A) Atomic Mass unit (amu) Isotopes
Atomic terms
Atomic Number (Z)
Mass Number (A)
Atomic Mass unit (amu)
Isotopes

13. Atomic Number (Z): Number of Protons
In a neutral atom the # of protons = number of electrons
P+ = e-
14+ = 14-

14. Mass Number Always a whole number. # of neutrons = A - Z
Total # of nucleons (protons + neutrons) in nucleus of atom.
# of P+ (+) # of n-
© Addison-Wesley Publishing Company, Inc.
Always a whole number.
# of neutrons = A - Z
# of neutrons = mass # - atomic #

15. Atomic Mass 1 proton = 1 u 1 neutron = 1 u 1 u = 1.67  10-24 g
atomic mass unit (amu) = unit to describe the mass of an atom
1 u = 1/12 the mass of a 12C atom
1 proton = 1 u 1 neutron = 1 u
1 u = 1.67  g

16. Particle Symbol Charge Electron e" -1 Proton P+ +1 1 amu Neutron
Mass in amu
Mass in grams
Electron
e" -1
1/1 840 amu
9.11 x 10-28g
Proton P+ +1
1 amu
1.67 x 10-24g
Neutron
N+- or n0
1.67 x g
© Addison-Wesley Publishing Company, Inc.

17. We’ve only just begun…….