Transcript chpt 11 and 12 notes with answers

Name: ________________
Class: ___________
History of the atom:
https://www.youtube.com/watch?v=NSAgLvKOPLQ
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440 BCE… first atomic theory by Democritus
◦ Atom: Greek meaning “not able to be divide”
 Small hard particles that make up stuff (matter)
 Countered by Aristotle, stated never end up with
something that cannot be divided
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John Dalton came up with the new theory
◦ 1700’s scientists learn elements combine in certain
proportions based on mass
◦ 1803 theory
 All substances made up of atoms
 Atoms of the same elements are exactly alike
 Atoms join with other atoms to make new substances
(Not quite correct)
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J.J. Thomspon discovered atoms are
composed of smaller particles
◦ Discovered negative particles which he named
ELECTRONS
◦ Plum-Pudding Model: electrons are located all
around an atom
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1909: experimented with “plum pudding” and
discovered atoms more of a solid substance
1911: Revised theory to state center of atom
has a nucleus (dense positively charged area)
and electrons surround and are repelled by
nucleus
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1913: electrons move around the nucleus in
certain paths, energy levels
Electron can “jump” paths
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Explained the nature of electrons in added
◦ Do not travel in definite paths; paths cannot be
predicted
◦ Theory states; there are regions in an atom where
electrons are likely to be found called clouds
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the smallest part of an
element that has all the
element’s properties.
Composed of PROTONS
and NEUTRONS and
(found in the nucleus)
ELECTRONS that
revolve swiftly around
the nucleus.
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PROTONS are positively
charged particles
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NEUTRONS have no charge,
but have mass
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ELECTRONS are smallest and
electrically negative
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The number of Protons and
Electron ARE EQUAL
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ATOMIC NUMBER is equal to
the number of electrons which
is also the proton number
◦ ALWAYS A WHOLE NUMBER
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ATOMIC MASS is the number
of neutrons and protons.
◦ HAS DECIMALS DUE TO
NEUTRONS
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Electrons swarm around the nucleus of an
atom in layers “clouds”
Each cloud has a minimum and maximum
number of electrons it can hold
The maximum number of layers is 7
The maximum number of electrons in each
level is respectfully inner to outer: 2, 8, 8, 18,
18, 32, and 32
Name: ________________
Class: ___________
https://www.youtube.com/watch?v=s
Wwd5vks9n8
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Scientists were needing a way to arrange the
elements.
1869: Dmitri Mendeleev arranged elements
by increasing atomic mass and discovered a
pattern called “PERIODS”
Wasn’t a perfect fit, and needed retuning
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1914: Henry Moseley arranged the elements
by atomic number
Solved the problem of missing
elements/spaces in the table
Periodic Law: the physical and chemical
properties of an element changes with its
atomic number
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Organize the atoms by their elements
Classified by similar CHEMICAL
CHARACTERISTICS(columns/groups) and
INCREASING ATOMIC NUMBER (rows/periods)
Location will help you predict how it will react
with others in bonding.
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Metals
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Nonmetals
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Metalloids
◦ Found on the left of the
periodic table
◦ Few electrons in outer shell
◦ Solids
◦ Right if the “zigzag” line on
periodic table
◦ Almost complete electron
shells
◦ Mostly gases at room
temperature
◦ “semiconductors”
◦ Border left side of “zigzag”
◦ Varying number of
electrons in outer shell
◦ Share properties of both
metals and nonmetals
https://www.youtube.com/watch?v=VgVQKCcf
wnU
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Each element has a symbol made from its
name; either English or Latin root
Rows are the periods that show a pattern of
change in physical and chemical properties
are you move across left to right
Vertical columns are groups/families
◦ Similar chemical/physical prosperities
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Each group of elements share similar
properties
Most family names are the name of the
element at the top of the column
Some family names are notable based on
certain traits
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Group 1
Most reactive metals, the bottom element,
Francium, is the most reactive element
known.
◦ Stored in oil to keep from reacting with air
(moisture)
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1 electron in their outermost shell
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Group 2
2 electrons in the
outermost shell
Less reactive than
group 1
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Transition Metals,
columns 3 to 12
Less reactive than group
1 or 2
Usually have 1 to 2
electrons in outermost
shell, (except mercury)
Good conductors of
thermal energy and
electricity
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Appear in separate “rows” outside the body of the
table
Elements have very similar properties
Lanthanides: shiny, reactive metals
Actinides: radioactive or unstable
◦ ELEMENTS HIGHER THAN 94 ARE NOT FOUND
NATURALLY; PRODUCED IN LABORATORIES
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Group #13
Contains 1 metalloid and 4 metal
elements
3 electrons in outer level
Solids at room temperature
Most common element is
Aluminum
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Group 14
1 nonmetal, two
metalloids, 2 metals
4 electrons in the
outermost shell
Reactivity varies
among elements
Solid at room
temperature
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Group 15
2 nonmetals, 2
metalloids, and 1 metal
5 electrons in
outermost shell
Reactivity varies with
elements
Solid at room
temperature (except
nitrogen)
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Group 16
Three nonmetals, one metalloid, 1
metal
6 electrons in the outermost level
Reactive to other elements
All but oxygen are solids at room
temperature
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Group 17
Nonmetal elements
7 electrons in outermost shell
Very reactive; VIOLENT reactions with alkali
metals to form salts; never found by self in
nature
Poor conductors of electric current
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Group 18
Nonmetal elements
8 electrons in outermost shell; except Helium
which is 2
UNREACTIVE
Colorless, odorless gases at room
temperature
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Properties are unique to itself
most abundant element in
universe
1 electron in outermost shell
Colorless, odorless gas at
room temperature
Low density
EXPLOSIVE REACTIONS WITH
OXYGEN