Atomic
Structure
John Dalton’s
Atomic Theory
All Matter is Composed
of Tiny Particles Called
Atoms
1.
All Atoms of a Given
Element have Identical
Weights
2.
Atoms of One Element
Combine with Atoms of
Another Element in
Definate Proportions.
3.
Atoms are Indivisible in
Chemical Changes.
Atoms are not Created
nor Destroyed only
Rearranged
4.
J.J. Thomson
The electron
Ernest Rutherford
Gold Foil Experiment
Atomic Structure
James Chadwick
Credited with
the discovery
of the
neutron
MILIKAN’S OIL DROP EXPERIMENT
Millikan oil-drop
experiment, first direct
and compelling
measurement of the
electric charge of a
single electron.
Measured the
minute electric
charge that is present
on many of the droplets
in an oil mist.
IONS
Charged particles due to the loss or gain of electrons.
Metals: Lose electrons to form positive ions called cations. (ca+ions)
Non-metals: Gain electrons to form negative ions called anions.
A neutral atom of chlorine: Cl
17 protons (+) 17 electrons (-)
A chloride ion: Cl-
17 protons (+) 18 electrons (-)
CHLORINE ATOM CHLORIDE ION
WHICH PAIR REPRESENT
ISOTOPES?
A 12C, 12N
B 55Mn2+, 55Mn3+
C. 32S, 33S
WHICH PAIR REPRESENT
ISOTOPES?
A 12C, 12N
B 25Mn2+, 25Mn3+
C. 32S, 33S
WHICH PAIR HAVE THE SAME
NUMBER OF NEUTRONS?
A. 40Ca, 39K
B. 31P, 32P
C. 107Pd, 107Ag
WHICH PAIR HAVE THE SAME
NUMBER OF NEUTRONS?
A. 40Ca, 39K
B. 31P, 32P
C. 107Pd, 107Ag
SYMBOL e- Z A
n1
0
As-3
42
36 38 127
46 50 69
-I131
SYMBOL e- Z A
n1
0
As-3
36 33 75 42
Sr+2
36 38 127 89
Sn+4
46 50 119 69
-I131 54 53 131 78
Homework
Page 77 #6, 9, 11, 12, 17, 18, 23,
24, 28, 30, 33, 41, 47, 51, 53-57,
59, 114, 125
CP
Page 77 # 1-18, 22-32, 34, 36,
38, 42