1. Empedocles, a Greek philosopher active around 450 B. C
Empedocles, a Greek philosopher active around 450 B.C. proposed 4 fundamental substances, fire, water, air ,earth. Formulating the idea of elemental substances

2. Democritus, 420 B.C. wrote that all matter was made up of small, indivisible particles he termed “atoms”.

4. 3. Law of multiple proportions

5. 4. In a chemical reaction – atoms move around and may change their order with respect to one another but, the atoms themselves don’t change

6. Pure substances can be a single atoms or ions or compounds with definite formulas

9. Separation of mixtures
physical
filtration

10. Separation of Homogeneous mixtures
Distillation
Thin Layer Chromatography

11. Law of Conservation of Mass Mass cannot be created nor can it be destroyed
An automobile holds 21 kg of gasoline. When the gasoline burns 84 kg of oxygen is consumed, and carbon dioxide and water are produced. What is the total combined mass of carbon dioxide and water that is produced?

12. Law of Multiple proportions
Upon decomposition, one sample of magnesium fluoride produced 1.65 kg of magnesium and 2.57 kg of fluorine. A second sample produced 1.32 kg of magnesium. How much fluorine (in grams) did the second sample produce?

14. Millikan discovered the charge on an electron using the oil drop experiment

16. Discovery of the neutron, Chadwick

17. Particle
Mass in grams
Charge in Coulombs
Unit charge
Electron
9.1x10-28
-1.6x10-19 -1
Proton
1.67x10-24
+1.6x10-19 +1
neutron

18. Fluorine atom Bohr model

19. Bohr model of gold atom How many electrons?

20. notation

21. Fluoride ion

22. Write notations for the following
a. Iodine-127 ( number denotes A)
b. Aluminum-27 (3+ cation)
c. Sulfur-32 (2- anion)

23. Splitting the atom
Atoms lose their physical properties that make
them unique
Large amounts of energy released
Binding energy : energy that binds subatomic particle together

24. Isotopes: atoms with the same number of protons but different number of neutrons

25. All isotopes of the same element have the same atomic number

26. Mass spectrometer stick diagram for
Boron

28. For the previous slide 1. if there is 5.0 g 202Hg in the sample
How many grams of 198 Hg is in the sample?
How many grams of 204 Hg is in the sample?

30. Average atomic mass

35. Average atomic mass example problems
Three naturally occurring isotopes of magnesium have masses of , , and u. Their abundances are 78.70%, 10.13%, and 11.17% respectively. Calculate the chemical atomic weight of magnesium.

36. Average atomic mass practice exercise
Gallium has two naturally occurring isotopes 69Ga and 71Ga with masses of amu and amu, respectively. Calculate the percent abundances of these isotopes of Gallium.

37. Periodic table

38. Metals and non metals

39. Groups and Periods

40. Groups numbers and names

44. Halogens group 7 Reactive Form anions
Depending on the element can be Gas, liquid or solid at room temperature

45. Noble (Inert gases) Group 8
Only Xenon reacts, have 8 electrons in valence shell, all are
gases at RT

46. Predictable monatomic charges