- 1. Advanced Chemistry Chapter 2 Atoms, Molecules, and Ions
2. 2.1 Early Chemistry 3. Early Chemistry
- The Greeks the first to try and explain chemical changes
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- Proposed that all matter was composed of four fundamental
substances.
4. Early Chemistry
- Demokritos (also Greek) believed that matter was composed of
small, indivisible particles.
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- Atomos term used to describe these particles.
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- Greeks were without the ability to test these hypothesis and no
definite conclusion was reached.
- Alchemy predominate pseudoscience that dominated the next 2000
years.
5. Modern Chemistry
- The foundations were laid in the sixteenth century
- The first chemist to perform quantitative experiments was
Robert Boyle (1627-1691)
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- Published relationship between pressure and volume
6. 2.2 Fundamental Chemistry Laws 7. Fundamental Chemical
Laws
- Law of Conservation of Mass Mass is neither created nor
destroyed in a chemical reaction.
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- Verified by Lavoisier (1743 1794) through his quantitative
studies of combustion.
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- Lavoisier presented the most unified and complete knowledge of
chemistry to date.
8. Fundamental Chemical Laws
- Law of Definite Proportion a given compound always contains
exactly the same proportion of elements by mass.
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- Prousts (1754-1826) discovery was made through careful
experiments regarding composition.
9. Fundamental Chemical Laws
- Law of Multiple Proportions when two elements form a series of
compounds, the ratios of the masses of the second element that
combine with mass of the first element can always be reduced to
small whole numbers.
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- Dalton (1766-1844)discovered that carbon and oxygen form two
different compounds that contain different relative amounts of
carbon and oxygen.
10. Daltons Atomic Theory 11. Daltons Atomic Theory
- Each element is made up of tiny particles called atoms.
- The atoms of a given element are identical; the atoms of
different elements are different in some fundamental way or
ways.
12. Daltons Atomic Theory
- Chemical compounds are formed when atoms of different elements
combine with each other.A given compound always has the same
relative numbers and types of atoms.
- Chemical reactions involve reorganization of the atoms- changes
in the way they are bound together.The atoms themselves are not
changed in a chemical reaction.
13. Daltons Table of Atomic Masses
- Dalton prepared the first table of atomic masses
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- Many of the masses were later found to be wrong
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- Dalton still provided an important step with table
construction.
14. Gay-Lussac
- Joseph Gay-Lussac (1778-1850) provided the keys to determining
the absolute formulas for compounds by his experimental work.
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- Performed experiments under the same conditions of temperature
and pressure and determined the amount of gases that would
react.
15. Amadeo Avogadro
- Avogadros hypothesis at the same temperature and pressure,
equal volumes of different gases contain the same number of
particles.
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- The volume of gas is determined by the number of molecules
present and not the size of the individual particles.
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- Avogadros number 6.02 x 10 23
16. 2.4 Early Experiments to Characterize the Atom 17. The
Electron
- Cathode-Ray Tube a high voltage applied to a tube produced a
ray (cathode ray).The ray was produced at the negative electrode
and was repelled by the negative pole of an applied electric
current.Thomson (1898-1903) concluded that the ray was a stream of
negatively charged particles.
18. Deflection of Cathode Rays by an Applied Electric Field 19.
Video
- http://www.youtube.com/watch?v=7YHwMWcxeX8
20. The Electron
- Millikan discovered the Charge-to-mass ratio of an electron
with his oil drop experiment.
21. A Schematic Representation of the Apparatus Millikan Used to
Determine the Charge on the Electron 22. The Electron
- Plum Pudding Model Thomson postulated that atoms must have a
cloud of positive charge in order to counter the random negatively
charged electrons.
23. The Plum Pudding Model of the Atom 24. Radioactivity
- Three types of radioactivity:
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- Gamma ( ) rays is high-energy light
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- Beta () particles high speed electron
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- Alpha () particles Helium nucleus (+2 charge)
25. The Nuclear Atom
- Rutherford tested Thomsons plum pudding model by sending a
stream of particles through a thin sheet of metal foil.
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- The alpha particles were scattered and reflected concluding
that a dense center of the atom existed.
26. Rutherford's Experiment Ona -Particle Bombardment of Metal
Foil 27. (a) Expected Results of the Metal Foil Experiment if
Thomson's Model Were Correct(b) Actual Results 28. 2.5 The Modern
View of Atomic Structure: Intro 29. Atomic Structure
- Protons 1 amu (1.673 x 10 -27kg);+1 charge
- Neutrons 1 amu ; no charge
- Electrons (9.109 x 10 -31kg) ; -1 charge
30. Two Isotopes of Sodium 31. Writing Symbols for Atoms
- Atomic number(number of protons) is written as a
subscript.
- Mass number ( total number of protons and neutrons) written as
a superscript.
32. 2.6 Molecules and Ions 33. Molecules
- Chemical Bonds - the forces that hold atoms together in
compounds
- Chemical formula symbols for the elements are used to indicate
the types of atoms present and subscripts are used to indicate the
relative numbers of atoms.
34. Molecules
- Structural formula individual bonds are shown (indicated by
lines) between element symbols.
- Space- filling model shows the relative sized of the atoms as
well as their relative orientation in the molecule.
- Ball-and-stick model also used to represent molecules.
35. Space-Filling Model of Methane 36. Ball-and-Stick Model of
Methane 37. Ball-and-Stick Models of the Ammonium Ion and the
Nitrate Ion 38. The Structural Formula for Methane 39.
Molecules
- Covalent bonds sharing electrons to form amolecule .
- Ionic bond a force of attraction between oppositely charged
ions that form acompound.
40. Ions
- Ion is an atom or group of atoms that has a net positive or
negative charge.
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- Anion ion with a negative charge.
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- Cation ion with a positive charge.
- Polyatomic Ion a compound consisting of many ions.
41. 2.7 An Introduction to the Periodic Table 42. Periodic
Table
- Most elements are metals.
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- Efficient conduction so heat and electricity
43. Periodic Table
- Nonmetals the relative few appear on the upper right corner of
the table. (right of the heavy line)
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- Bond together forming covalent bonds.
44. Periodic Table
- Groups/Families (vertical columns in table)Have similar
chemical properties due to their similar atomic structure.
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- Alkali metals group 1A readily form +1 ions
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- Alkaline earth metals group 2A readily form +2 ions
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- Halogens group 7A all form diatomic molecules and react with
metals to form salts readily form-1 ions.
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- Noble gases all exist under normal conditions as monatomic and
have little chemical reactivity.
45. Periodic Table
- Periods horizontal rows that represent the energy levels of the
elements.
46. The Periodic Table 47. 2.8 Naming Simple Compounds 48.
Binary Ionic Compounds Type I
- The cation is always named first and the anion second
- A monatomic (one atom) cation takes its name from the name of
the element.
- A monatomic anion is named by taking the root of the element
name and adding ide.
49. Binary Ionic Examples
50. Binary Examples
51. Common Monatomic Cations and Anions 52. Binary Ionic
Compounds Type 2
- The charge on the metal ion must be specified.
- Roman numerals indicate the charge of the cation.
53. Binary (Type 2) Examples
54. Common Cations and Anions 55. Common Type 2 Cations 56.
Ionic Compounds: Polyatomic Ions
- Oxyanions anions that contain an atom of a given element and
different numbers of oxygen atoms.
57. Oxyanions
- -ite the name of the one with the smaller number of oxygen
atoms.
- -atethe name of the one with the larger number of oxygen
atoms
58. Oxyanions
- When more than two oxyanions make up a series the following
prefixes apply:
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- Hypo- (less than) the least amount of oxygen atoms
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- Per- (more than) the most amount of oxygen atoms
59. Polyatomic Ions
- Potassium dihydrogen phosphate
60. Common Polyatomic Ions 61. Binary Covalent Compounds
- The first element in the formula is named first, using the full
element name.
- The second element is named as if it were an anion
- Prefixes are used to denote the numbers of atoms present
- The prefix mono- is never used for naming the first
element.
62. Prefixes Used in Covalent Compounds Prefix Number Indicated
mono 1 di 2 tri 3 tetra 4 penta 5 hexa 6 hepta 7 octa 8 nona 9 deca
10 63. Binary Covalent Compounds
64. A Flowchart for Naming Binary Compounds 65. Naming Chemical
Compounds 66. Acids
- Binary acids the acid is named with the prefix hydro- and the
anion ends in ic.Add the name acid on the end.
67. Names of Acids* that Do Not Contain Oxygen 68. Acids with
Oxygen
- If the anion ends in ate, the suffix ic is added to the
root.
- If the anion has an ite, the suffix ous is added to the
root.
- Add the name acid to the end.
69. Acids
70. Names of Some Oxygen-Containing Acids 71. Figure 2.25Naming
Acids 72. Figure 2.7A Cathode-Ray Tube 73. Plant is Newly
Discovered Source of Gold 74. Figure 2.1The Priestley Medal is the
Highest Honor Given by the American Chemical Society 75. A Silicon
Chip 76. Atomic Nucleus 77. Crystals of Copper(II) Sulfate 78.
Various Chromium Compounds Dissolved in Water 79. Table 2.1The Mass
and Charge of the Electron, Proton, and Neutron 80. Table 2.2The
Symbols for the Elements That Are Based on the Original Names 81.
Table 2.6Prefixes Used to Indicate Number in Chemical Names