1. Chemical Building Blocks
Atomic theories, models and electronic structure

2. QUIZ: ½ sheet of paper
An analyst measured a 3.3 x 10-2 L sample and found it weighed 385 mg. Report its density in g/mL. (Proper SF)
Give an example of the ff.
A colloid
A pure substance
An intensive property
An extensive property
A chemical property
Parts of the atom (3pts., bonus of 1 pt. each for other subatomic particles)

3. History of the Atomic Theory

4. Dalton’s Atomic Theory
Matter is composed of extremely small particles called atoms.
All atoms of a given element are identical, having the same size, mass and chemical properties. The atoms of one element are different from the atoms of all other elements.
Compounds are composed of atoms of different elements combined in fixed proportions.
Chemical reactions only involve the rearrangement of atoms. Atoms are not created or destroyed in chemical reactions.

5. Law of Conservation of Mass

6. Law of Multiple Proportions

7. Cathode Ray Tube

8. Cathode ray tube television

11. Radioactivity

12. (Uranium compound)

13. Atomic Models
Plum pudding model

14. Rutherford’s gold foil experiment

15. Rutherford’s atomic model

16. Discovery of the Neutron
Chadwick’s equation:

17. Parts of the atom Protons Electrons Neutrons
Atomic number and mass number
isotopes

18. Test Yourself!
How many neutrons are there in the 90Sr nucleus?
A rubidium isotope has 50 neutrons. What is its mass no.?
How many neutrons does 90Mo have?
How many neutrons are in bromine-81?
Which of the following isotopes are of the same element? Name the isotopes.
X X X X X

19. Electromagnetic spectrum

20. Photoelectric effect
Einstein

21. Continuous vs. Line Spectra

22. Bohr’s Model
Allowed energy states
Energy is quantized (flame test)

23. Heisenberg’s uncertainty principle
An observer always has an effect on the observed
Location and momentum of electron
Schrodinger’s wave equations: quantum numbers (n, l, m, ms)

24. Orbitals

25. Possible orientations of d-orbitals

26. The f orbitals

27. Orbital energy levels in hrdrogen atom
Energy only depends on principal quantum number n
n=3
n=2
n=1

28. Orbital energy levels in multi-electron atom
Energy depends on n and l
n=3 l = 2
n=3 l = 1
n=3 l = 0
n=2 l = 1
n=2 l = 0
n=1 l = 0

29. Outermost subshell containing electrons

30. Additional exercises
For n=4, what are the possible values of l and ml?
Which of the following are permissible sets of quantum numbers for an electron in a hydrogen atom? (n,l,ml)
(2,2,-2)
(4,3,-1)
(1,0,0)
(6,3,-4)