Download CHAPTER 3—ATOMIC STRUCTURE

CHAPTER 3—ATOMIC STRUCTURE
CHEMISTRY-CP
MS. WACK
OBJECTIVES:
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Distinguish between a mixture, an element and a compound
Distinguish between homogeneous and heterogeneous mixtures
Separate mixtures using various techniques
Define and identify pure substances
Identify and give the chemical symbols of elements
Define compound and describe what a chemical formula details
Create a timeline of the development of the atomic model
Describe and model the development of the atom over time
Describe a cathode ray tube and how it relates to modern times
Define the law of conservation of mass and constant composition
Define, locate and determine the charge and mass of electrons, protons and neutrons
List radioactive elements
Explain how scanning tunneling microscopy works
Define and use atomic number
Define isotopes
Determine the atomic mass of an element
Write isotopic symbols
Calculate mass number
Matter
Pure Substance
Element
Mixture
Compound
Heterogeneous
Homogeneous
Solution
Solute
Solvent
2-3 Matter (text pp. 39-42)
- Matter:
Types of Observations
Macroscopic Observations:
Microscopic Observations:
Submicroscopic Observations:
Quantitative Observation:
Qualitative Observations
Properties
Physical Properties:
Examples of Physical Properties of Matter
Chemical Properties:
Examples of Chemical Properties of Matter:
Types of Matter (txt pp 45-52)
1) Mixture:
How can you tell if a substance is a mixture?
Heterogeneous Mixture:
Examples:
Homogeneous Mixture:
Examples:
Solution:
Solute:
Solvent:
Example: In a Kool-Aid mixture, what is the solute and what is the solvent?
Aqueous Solution:
Alloy:
Examples of Alloys:
-Can you separate a mixture?
Filtration:
Magnet:
Distillation:
Crystallization:
Chromatography:
2) Pure Substances:
Element:
-The naming of elements:
-Chemical Symbol:
-How can you tell whether or not a substance is an element?
-Can you separate an element?
Examples: Give the chemical symbols of the following elements:
Aluminum ________
Gold __________
Tin ___________
Compound:
Chemical formula:
Subscript:
How can you tell whether or not a substance is a compound?
Example: The chemical formula of baking soda is NaHCO3. What does this tell you about
baking soda?
Example: The chemical formula of a substance is Mg(OH)2. Which elements are present
and how many of each element are there?
Can you separate a compound?
Atomic Models (txt pp. 101-108)
-450 B.C.—Democritus
Atom:
-Problem with Democritus’ Theory:
-Aristotle:
-1700’s—Antoine Lavoisier:
Model
Law of Conservation of Mass:
Example: If you begin a chemical reaction with 5 grams of
reactant, how much product will be formed at the end of the
reaction?
Example: If 2 atoms of oxygen are present at the beginning of a chemical
reaction, how many atoms of oxygen will be present at the end of the chemical
reaction?
-1799—Joseph Louis Proust:
Law of Constant (Definite) Proportions:
Malachite
Always the same composition
-1803—John Dalton:
-Atomic Theory of Matter:
Section 3-2 Discovering Atomic Structure (pp. 95-102)
-1700’s—Benjamin Franklin:
-1839—Michael Faraday:
-Electricity:
-Static:
-Static Electricity:
Model
1800’s—Cathode Ray Tube:
_____________________ use Cathode Ray Tubes
-1896—J.J. Thomson
-measured:
-discovered:
-Model:
-electron:
-1896—Henri Becquerel
-radioactivity:
-Marie Curie & Pierre Curie:
-radioactive elements:
Model
-1909—Robert Millikan:
Oil Drop Experiment:
early 1900’s—Ernest Rutherford:
Model
-Experiment:
-alpha () particles:
-beta () particles:
-gamma () radiation:
-Model:
-nucleus:
-proton:
-1930—James Chadwick
-neutron:
Distinguishing Among Atoms (txt pp. 110-117)
-Scanning Tunneling Microscope (STM)
-Atoms are composed of:
Explains:
-Other particles in an atom:
-Impact of these particles on our understanding of chemistry:
Structure of the Atom
Particle
Location
Charge (C)
Relative
Charge
Mass(g)
Proton
+1.602 x 10-19
1.673 x 10-24
Neutron
0
1.675 x 10-24
Electron
-1.602 x 10-19
9.109 x 10-28
Relative Mass
(amu)
-amu =
Atomic Number:
Also equals the __________________________________________ in an atom because:
The atomic number is used to _______________________________________________
because:
The periodic table is arranged by _____________________________________.
Examples:
a) What is the atomic number of xenon?
b) How many protons does tungsten have?
c) How many electrons does rutherfordium have?
d) Which element has 98 protons?
e) Which element has 22 electrons?
f) What element has an atomic number of 44?
Isotopes:
What’s the definition mean?
Isotopes of the same element are:
Examples of Isotopes:
Mass Number:
Mass Number =
The mass number must be __________________________ it cannot be found on
the _____________________________________.
Neutrons =
Examples:
a) What is the mass number of an atom with 17 protons and 20 neutrons?
b) How many neutrons does a carbon atom with a mass number of 14 have?
Isotopic Symbol:
Naming an Isotope:
Example: Write the isotopic symbol and name for the following atoms
a) 21 protons, 24 neutrons
b) 53 protons, 74 neutrons
c) How many protons, electrons and neutrons are in an atom of 3215P?
Atomic Mass:
Atomic Mass Unit:
=
Atomic mass is different from _______________________________
Atomic mass is found on the _________________________________.
The value found on the periodic table for atomic mass will be closest to:
To calculate atomic mass:
Example: Calculate the atomic mass of carbon if carbon-12 has a percent abundance of
98.89% and carbon-13 has a percent abundance of 1.11%.