Download Chapter 2choutline - Madison County Schools

Name ________________________________
Date ____________________ Block _______
Chapter 2 Outline
“Matter is made up of Atoms”
History
Greeks
 Proposed
that matter
was made up
of four
elements
(________,
_________,
earth, & fire)
 Did not test
their
__________
with
experiments
Democritus
 Proposed that
the world is
made up of
empty space
and tiny
particles called
___________
 Thought that
atoms were the
_____________
particles of
matter and
that different
types of atoms
exist for every
type of
_____________
Antoine Lavoisier
 Made
_____________
of chemical
changes in a
sealed
container
 Observed that
the _________
of reactants
before a
chemical
reaction was
equal to the
mass of
_____________
after reaction
 conclusions
became known
as __________
_____________
_____________
_____________
Joseph Proust
 observed that the
composition of
_____________ is
always 11 %
hydrogen and 89 %
_______________by
mass, regardless of
source
 observed other
compounds and
noticed that the
_________________
that made up
compound was
always in a certain
_________________
by mass
 principle referred to
as law of definite
proportions
John Dalton
 studied results of
Lavoisier, Proust,
and others
 proposed his
__________________
in 1803 which states
1. all matter is
made up of
____________
2. atoms are
____________
and cannot be
divided into
smaller
particles
3. all atoms of
one_________
are exactly
alike, but
they are
different from
____________
of other
elements
Atomic Theory, Conservation of Matter, and Recycling
When waste is burned or buried in a land fill, the atoms of the waste may combine with
oxygen or other substances to form _____________________________. In natural processes,
atoms are not destroyed; they are ___________________________.
Hypotheses, Theories, and Laws
The first step to solving a problem is _______________________. Afterwards, a hypothesis is
formed which is a _______________________ prediction to explain observations. To find out
if a hypothesis is correct, it must be tested by ____________________________ experiments.
Scientists develop theories to organize knowledge. A theory is an _______________________
based on many observations and __________________________ by the results of many
experiments. A scientific theory is heavily supported by __________________________ gained
from experiments and continual observations. Theories explain laws, which is simply a fact
of nature that is _____________________ so often that it becomes accepted as truth. A law
does not explain why something happens.
The Discovery of Atomic Structure
J.J. Thomson performed an experiment that discovered the existence of the ______________.
Thomson’s experiments involved the use of cathode-ray tubes. He found that the rays bent
toward a _____________________ charged plate and away from a
___________________charged plate. From Thomson’s experiments, scientists concluded that
atoms were made up of smaller particles called __________________________.
Particles of an Atom
Subatomic Particle
Proton
Neutron
Electron
Symbol
P+
n0
e-
Charge
+1
0
-1
Mass in Grams
1.67 X 10-24
1.67 X 10-24
9.11 X 10-28
Mass in u
Information in Each Block of the Periodic Table
hjkh
Chlorine
17
Cl
35.453
Atomic Number and Masses
The atomic number of an element is the number of _______________ in the ______________.
(chlorine has ____protons) It is the number of protons that determines the ________________
of an element. Because atoms have no overall electrical charge, an atom must have as many
____________________as there are protons in its nucleus. Therefore, the atomic number also
tells the number of electrons in a ___________________atom. (chlorine has ______ electrons)
The sum of the _________________ and __________________ in the nucleus is the mass
number. It is the rounded atomic mass (mass number of chlorine is _____)
To calculate the number neutrons of an atom subtract the mass number from the atomic
number (chlorine has ______neutrons)
Isotopes are atoms of the same element that differ in __________________ and number of
neutrons (they have the same number of protons)
Isotopes are identified by writing the name or symbol of element followed by its ___________
____________ (Cl-37 or chlorine-37)
The atomic mass found in the box on the periodic table is the _________________ atomic
mass of that element. This number is the weighted average mass of all the naturally
occurring __________________________ of that element.
Electrons in Atoms
Niels Bohr proposed that electrons must have enough energy to keep them in constant motion
around the ____________________. Bohr’s planetary model theorized that electrons must
have energy of motion that enables them to overcome the attraction of the _______________
nucleus. This energy keeps the electrons moving around the nucleus.
Gamma rays
Visible light
Infrared
Radio waves
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The Electromagnetic Spectrum
highest frequency, shortest ______________________
can pass through most surfaces
lower frequencies than _______________________
pass through soft body tissue but stopped by _____________
slightly more energetic than visible light waves
part of ________________________ that causes sunburn
sensitive to human eyes; eyes and brain interpret different
frequencies as different _________________
less energy than ____________________
given off by the ____________________ and most warm objects
lowest ________________ on the electromagnetic spectrum
frequency range in the AM radio band is from ____________ to
____________and wavelengths from about _____________ to
______________
low-frequency, low-energy waves; used for __________________
and ___________________
The Electron Cloud Model
The electron cloud model states that energy levels are ____________________regions of
space around the nucleus in which _______________ are most likely found. The spherical
regions where electrons travel may be depicted as ________________ around the nucleus.
The space around the _________________of an atom where the atom’s electrons are found is
called the electron cloud.
The regions of space in which electrons can move about the nucleus of an atom are called
_____________________________. Each energy level can hold a limited number of
________________________. The lowest energy level is the _________________________ and
___________________ to the nucleus. The first energy level holds a maximum of __________
electrons. The second energy level is _________________ because it is farther away from the
nucleus. It holds a maximum of _____________ electrons. The third energy level holds a
maximum of ______________ electrons.
The electrons in the outermost energy level are called _______________________. The
valence electrons determine the chemical and ____________________ properties of an
element. Because valence electrons are so important to the ____________________ of an
atom, it is useful to represent them with symbols. A _______________________________
illustrates valence electrons as dots around the ____________________ of an element. The
element’s symbol represents the __________________ plus all the inner electrons.
Lewis Dot Diagrams
Li
Be
B
C
N
O
F
Ne