Download Chapter 4 Sec. 1-3 Atomic Structure NOTES

Chapter 4 Sec. 1-3 Atomic Structure NOTES

Sec. 1: Early History of the Atom and the Atomic Theory
o Democritus (Greek philosopher; 460-370 B.C.)
o
Aristotle (very influential Greek philosopher; 384-322 B.C.)
o
John Dalton (English schoolteacher; 1766-1844)


Dalton’s Atomic Theory
Sec. 2: Defining the Atom
o The Atom
o
o
The Electron
 Cathode Ray Tube

Sir William Crookes (English physicist)

J.J. Thompson (English physicist; 1856-1940)

Robert Millikan (American physicist; 1868-1953)

J.J. Thompson’s Plum Pudding Model
The Nucleus
 Ernest Rutherford (1871-1937)
 Gold Foil Experiment


James Chadwick (English physicist; Rutherford’s coworker; 1891-1974)
o
Neil’s Bohr (student of Rutherford)
o
Quantum Mechanical Model
Sec. 3 How Atoms Differ
o Atom
 Smallest particle of an element that retains the properties of that element
 Comes from the Greek word atomos, meaning indivisible
 Made up of 3 subatomic particles (electrons, neutrons, and protons)
o Subatomic Particles
Subatomic Particle
Symbol
Electron
Proton
Neutron
o
Vocabulary
 Atomic Number =

Atomic Mass =
Relative Charge
Relative Mass
o

Atomic Mass Unit (amu) =

Mass Number =

Isotopes =

Percent (%) Abundance =
Periodic Table Symbols and Elements
 Element = Nickel
 Symbol =

Symbol = Cr
 Element =

Practice Problem #1: What the symbol for the element Mercury?

Practice Problem #2: What is the element that has the symbol Ba?

Oxygen (O)

Atomic Number =

Atomic Mass =

# of protons =

# of electrons =

# of neutrons =

Tin (Sn)

Atomic Number =

Atomic Mass =

# of protons =

# of electrons =

# of neutrons =
o
Drawing of a Calcium Atom:
o
Nuclear Symbol

o
Write the nuclear symbol for U-238
Determine the # of p+, n, and e- for the following:

Ex #1) 63
29𝐶𝑢

Ex #2) P-31 (or Phosphorus-31)
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Ex #3) Niobium (use Periodic Table)
o
Calculating the atomic mass from an element’s isotopes (weighted average)

Avg. Atomic Mass = Mass Isotope1 (relative % abundance1) + Mass Isotope2 (relative %
abundance2) + …

Ex) Find the average atomic mass of Chlorine using the information in the table below.
Isotope
Cl-35
Cl-37
% Abundance
75.77%
24.23%
Mass (amu)
34.969
36.966