1. Atoms Molecules & Ions

2. Atomic Theory of Matter
Atoms – from the Greek word atomos meaning indivisible
John Dalton developed the Modern theory of the atom
In an attempt to explain how and why elements would combine with one another in fixed ratios and sometimes also in multiples of those ratios, Dalton formulated his atomic theory

3. elements consisted of tiny particles called atoms
all atoms of an element were identical and that in particular they had the same mass
compounds consisted of atoms of different elements combined. Compounds have constant composition because they contain a fixed ratio of atoms
chemical reactions involved the rearrangement of combinations of those atoms

4. Discovery of Atomic Structure
In 1897 the British physicist Joseph John (J. J.) Thomson (1856–1940) discovered the electron in a series of experiments
He studied nature of electric discharge in a high-vacuum cathode-ray tube
 Thomson interpreted the deflection of the rays by electrically charged plates and magnets as evidence of "bodies much smaller than atoms" 
He calculated the charge-to-mass ratio.

5. Figure: 02-04

6. In 1906, Millikan began experiments at the University of Chicago to attempt to measure individual electron charge
 use of oil drops

7. Diagram of Millikan's apparatus, from his Physical Review paper

8. Figure: 02-05

9.  Millikan showed that the charge of the droplets were always a whole number multiple of 1.592 x10-19C
 The accepted value is 1.602x10-19C
Millikan could now calculate the mass of an electron with Thomson’s ratio of charge to mass
      m = 9.10 X 10-28 g 

10. Radioactivity Spontaneous emission of radiation.
Rutherford discovered 3 types

11. Figure: 02-08

12. The Nuclear Atom
Thomson – Plum Pudding model

13. Figure: 02-09

14. Rutherford discovered a dense nucleus from his work with the gold foil expt

15. (a) Expected Results of the Metal Foil Experiment if Thomson's Model Were Correct (b) Actual Results

16. A Deeper Look into the Atom
Particle
Mass (kg)
Charge
Discoverer
Electron, e-
9.11E-31 -1
J.J. Thomson
Proton, p+
1.67E-27 +1
E. Rutherford
Neutron, n0
Chadwick
Other

17. Modern view of the atomic structure
The atom consists of protons (p+), electrons(e-), and neutrons(no).
Atoms are electrically neutral (#p+ = #e-)
An atom is defined by #p+ = Z = atomic number
As single atom is measured in amu ( 1 amu = x g)
An atomic ion is #p+ ≠ #e- resulting in a net nonzero charge on the species

18. Isotope
Atoms which have the same Z (same # p+) but a different A (different # n0)
Most elements have isotopes that occur in nature in precise proportions (fractional abundances, %).

19. Naturally occurring C: 98.892 % 12C + 1.108 % 13C.
Atomic Weights
Average Atomic Masses
Relative atomic mass: average masses of isotopes:
Naturally occurring C: % 12C % 13C.
Average mass of C:
( )(12 amu) + (0.0108)( ) = amu.
Atomic weight (AW) is also known as average atomic mass (atomic weight).
Atomic weights are listed on the periodic table.
Chapter 2

20. The Periodic Table

21. Periodic Table
An arrangement of elements according to increasing atomic number (Z)
Rows = periods
Columns = groups or families
Metals, Nonmetals, Semimetals
Main group (A), Transition Metals, Lanthanides and Actinides

22. Figure: 02-16

23. Chemical Bond Types IONIC: metal + nonmetal
COVALENT: nonmetal + nonmetal
METALLIC: metal + metal

24. Figure: 02-20a-h

25. Figure: 02-21

26. Names and Formulas for Acids
The names of acids are related to the names of anions:
-ide becomes hydro-….-ic acid;
-ate becomes -ic acid;
-ite becomes -ous acid.

27. Chapter 2

28. Some Simple Organic Compounds
Alkanes
Organic chemistry: the chemistry of carbon compounds.
Alkanes contain only C and H and are called hydrocarbons.
The names of alkanes all end in the suffix –ane.
Alkanes are named according to the number of C atoms in their backbone chain:
Methane has one C atom (CH4)
Ethane has two C atoms (CH3CH3)
Propane has three C atoms (CH3CH2CH3)

29. Some Derivatives of Alkanes
Replace H atoms in alkanes with heteroatoms (atoms other than C or H), we have introduced a functional group into the alkane
Replace H with –OH, then we form an alcohol.
Alcohols are also named by the number of C atoms.
Consider propanol: there are two places for the OH: on an end C or the middle C.
When the OH is located on the end C, we call the substance 1-propanol
When the OH is on the middle C, we have 2-propanol.

30. Replace a single bonds in an alkane with one or more double bonds, then we form alkenes.
Forming a double bond between C and O, forms carboxylic acids, ketones, aldehydes, and esters
Any organic molecule with double or triple bonds is called unsaturated.