Download Dalton`s Atomic Theory

A Brief History of Chemistry
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Ancient Greece
~_____ BCE
____________
Atomos-_________
Thought matter was
discreet
A Brief History of Chemistry
• Aristotle
• Thought matter was
________________
• Credited with 4 Greek
elements
• Earth
• Air
• Fire
• Water
A Brief History of Chemistry
• The Middle Ages
• ________________
• Europe-Convert base
metals to ________
• Asia- ____________
A Brief History of Chemistry
• Robert Boyle
• The Skeptical
Chemist
• The beginnings of
chemistry as an
_________________
_________________
A Brief History of Chemistry
• Antoine Lavoisier
• The father of modern
chemistry
• Law of ______________
of Mass
• Helped develop the
____________________
• Made first comprehensive
list of _______________
A Brief History of Chemistry
• John Dalton
• _________________
• 1803-1807
A Brief History of Chemistry
• 1867
• Dmitri Mendeleev
• _________________
A Brief History of Chemistry
• 1897
• J. J. Thomson
• Discovers
______________
A Brief History of Chemistry
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1911
Ernest Rutherford
Gold Foil Experiment
Discovered
__________________
• Discovered __________
in 1919
• James Chadwick
discovered the
_______________ in
1932
A Brief History of Chemistry
• The Manhattan
Project
• 1940’s
• The Atomic Bomb
The Law of Conservation of Mass
• Matter is neither
_________ nor
_________ during
chemical reactions or
during physical
changes.
The Law of Definite Proportions
• A chemical compound
contains the same
_________ in exactly
the same
_________________
by mass regardless of
the _________ of the
sample or _________
of the compound.
The Law of multiple Proportions
• If two or more different
compounds are
composed of the
__________________,
then the ratio of the
masses of the second
element combined with a
certain mass of the first
element is always a ratio
of __________________.
Dalton’s Atomic Theory
• All matter is made up
of _______________
called atoms.
• Atoms of a given
element are identical
in ______, ______,
and other properties.
• Atoms of different
elements _______ in
size, mass, and other
properties.
Dalton’s Atomic Theory
• Atoms cannot be
_________,
_________, or
_________.
• Atoms of different
elements can
combine in simple,
_________________
to form chemical
compounds.
Dalton’s Atomic Theory
• In chemical reactions
(rxns), atoms are
_________,
_________, or
_________.
Modern Atomic Theory
• All matter is composed of
__________________particles called
atoms.
• Atoms of the same element have the
same chemical properties, while atoms of
different elements have different
__________________.
Modern Atomic Theory
• While individual atoms of a given element
may not all have the same _________
(due to differences in nuclear structure),
any natural sample of the element will
have a definite __________________that
is characteristic of that element as
compared to any other element.
Modern Atomic Theory
• _________ are formed when atoms of 2 or
more elements unite, with each atom
losing its characteristic _________ as a
result of this combination.
• Atoms are not _________ in physical or
chemical rxns.
Discovery of the Electron
• 1897
• JJ Thomson
• Cathode Ray Tube
Experiment
• Discovered the
electron
Discovery of the Electron
• Air was evacuated
from the tube and an
electric current was
passed through it.
• A _________was
seen.
• When Thomson held
a magnet to the glow,
it was
_________________
the magnet.
Discovery of the Electron
• This meant that the
glowing field had an
_________________.
• Thomson had to work
out whether the glow
was
_________________.
• He placed a
________________
inside of the tube.
Discovery of the Electron
• If the wheel moved, the
glow was
__________________.
• If the wheel did not move,
the glow was _________.
• The wheel moved, so
Thomson knew that
____________________
_______were produced
by the current.
Mass of the electron
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1909
Robert Millikan
Oil Drop Experiment
Mass of electron
9.109 x 10-31kg
Plum Pudding Model
Rutherford’s Gold Foil Experiment
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1911
Ernest Rutherford
Gold Foil Experiment
Discovered the
atomic nucleus
The atom
• An atom is the smallest particle of an element
that retains the _______________ of that
element.
• The ___________ is a very small region located
at the center of an atom.
• The nucleus is made up of at least one positively
charged particle called a ___________ and
usually one or more neutral particles called
___________.
The atom
• Surrounding the nucleus is a region
occupied by negatively charged particles
called ______________.
• Protons, neutrons, and electrons are often
referred to as
_______________________.
Properties of Subatomic particles
Forces in the Nucleus
• When two protons are extremely close to
each other, there is a _______________
between them.
• A similar attraction exists when _______
are very close to each other or when
protons and neutrons are very close
together.
• The short-range proton-neutron, protonproton, and neutron-neutron forces that
hold the nuclear particles together are
referred to as _________________.
Nuclear Forces
Atomic Number
• Atoms of different elements have different
numbers of __________.
• Atoms of the same element all have the
_______ number of protons.
• The atomic number (Z) of an element is
the number of _________ of each atom of
that element.
Mass Number
• The mass number is
the total number of
_________________
that make up the
nucleus of an isotope.
Isotopes
• Isotopes are atoms of the same element that
have different __________.
• The isotopes of a particular element all have the
________ of protons and electrons but
_________ numbers of neutrons.
• Most of the elements consist of ________ of
isotopes.
Relative Atomic Mass
• The standard used by scientists to compare units
of atomic mass is the ______________ atom,
which has been arbitrarily assigned a mass of
exactly 12 atomic mass units, or 12 amu.
• One __________________, or 1 _____, is
exactly 1/12 the mass of a carbon-12 atom.
• The atomic mass of any atom is determined by
comparing it with the mass of the ___________
atom.
Average Atomic Mass
• Average atomic mass is the weighted average
of the atomic masses of the naturally occurring
_________ of an element.
• Calculating Average Atomic Mass
• The average atomic mass of an element
depends on both the _______ and the
___________________of each of the element’s
isotopes.
The mole
• A mole (abbreviated mol) is the amount of
a substance that contains as many
particles as there are atoms in exactly
_______ of carbon-12.
• The mole is the SI unit for amount of
___________.
• Avogadro’s number—6.022 1415 ×
1023—is the number of particles in
___________ of a pure substance.
Molar Mass
• The mass of __________ of a pure
substance is called the molar mass of that
substance.
• Molar mass is usually written in units of
_______.
• The molar mass of an element is
numerically equal to the atomic mass
of the element in _________________.
Molar Conversions
• What is the mass in grams of 3.50 mol of
the element copper, Cu?
Molar Conversions
• How many moles of silver, Ag, are in
3.01  1023 atoms of silver?