Transcript Atomic Structure and the Elements

Atomic Structure and the
History of the Atom
HISTORY
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Aristotle - One of
the most influential
Greek
philosophers,
whose theories
were wrong most
of the time. He
strongly opposed
the idea of the
atom. He believed
particles could be
infinitely divided.
Click here for
biography on Aristotle
HISTORY 2
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Click here for
biography on
Democritis
Democritus – A Greek philosopher,
and student of Aristotle. He
believed that things could be
divided until the division reached a
single particle that matter was
composed of, then the splitting
would stop when it reached
indivisible particles and wouldn’t go
on infinitely (forever).
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Believed that atoms could not be
created, destroyed, or further divided
History 3
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Dalton – An English
chemist who is
considered the
father of the modern
atomic theory. He
believed that all
elements are
composed of atoms
that cannot be
created, destroyed,
or further divided.
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biography on
Dalton
History 4
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Mendeleev – A Russian chemist,
developed a periodic table of
elements. He realized that the
chemical and physical properties
of the elements repeat in an
orderly way when elements are
organized according to
increasing atomic mass.
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biography on
Mendeleev
HISTORY5
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Science has come a long
way since Dalton, which has Click here for
biography on
made it necessary to update QUARKS
his atomic theory. Current belief is that
all elements are composed of atoms,
but we know that those atoms are not
indestructible. Atoms can be split
(chemically) in nuclear reactions, and
they are made up of even smaller
particles called quarks!
Period # and Group # INFO
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Period #
This number tells
you how many
rings to draw in
the Bohr’s model
of each of the
elements.
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Group #
This number tells
you how many
electrons can be
found in the last
ring of the Bohr’s
model.
Atom Vs. Ion
Exactly the same except for
the number of electrons
 Protons and neutrons NEVER
CHANGE
 Use the Bond # song which
matches the negative or
positive number at the at the
top of each column to
determine the ionic charge
 ANION = Negative ION
 CATION= Postive ION
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Bonding SONG
1bond,
2 bond,
3 bond, 4,
3 bond,
2 bond, 1
no more
ISOTOPES
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We also know that atoms of the same element
can have different masses, when they
represent different isotopes of that element.
1. Examples – Hydrogen has three
isotopes
a. Protium – 1 proton, 0 neutrons, 1
electron
b. Deuterium – 1 proton, 1 neutron, 1
electron
c. Trituim – 1 proton, 2 neutrons, 1
electron
Isotope VIDEO
How do we use Isotopes??
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Click
here
for the
video
What is Carbon Dating???
Click on the
picture to watch
a video about
carbon dating….
Periods VS. Groups
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Can you draw
the appropriate
structure of each
atom based on
their location
within the group?
Watch the video
and learn how!!
There are 2 group numbers…1 is the general group
going across the table and the other is the Valence
group number for 8 groups
Equals the number of shells located on the outside
of the nucleus where the electron orbitals are found
Why is the Periodic Table
important to me?
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The periodic table is
the most useful tool
to a chemist.
You get to use it on
every test.
It organizes lots of
information about all
the known
elements.
Families/groups on the
Periodic Table
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Columns are also
grouped into families.
Families may be one
column, or several
columns put together.
Families have names
rather than numbers.
(Just like your family
has a common last
name.)
Organization of Periodic Table
 Rows
are called periods.
 Columns are called families or
groups.
 All elements in a family have
similar properties.
METALS
NON-METALS
Metalloids
ALKALAI METALS
Aklaline earth metals
Lathanides
Actinides
BORON Family
Carbon Family
Nitrogen Family
Oxygen Family
HALOGENS
NOBLE GASES
Families on the Periodic Table
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Columns are also grouped
into families.
Families may be one
column, or several columns
put together.
Families have names
rather than numbers. (Just
like your family has a
common last name.)
Hydrogen
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Hydrogen belongs to a
family of its own.
Hydrogen is a diatomic,
reactive gas.
Hydrogen was involved in
the explosion of the
Hindenberg.
Hydrogen is promising as
an alternative fuel source
for automobiles
Alkali Metals
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first column on the
periodic table. (Group
1)
VERY Reactive
metals.
Extremely malleable
Will cause an
explosive reaction
when placed within
water
Alkaline Earth Metals
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Second column on the
periodic table. (Group
2)
Reactive metals that
are always combined
with nonmetals in
nature.
Several of these
elements are important
mineral nutrients (such
as Mg and Ca
GROUPS OF ELEMENTS IN
PERIODIC TABLE
METALS
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Vast majority of elements are metals.
Elements found to the left of the heavy
black line on periodic table.
Physical Properties:
Appearance – high luster
Tapping – malleable
Conductivity – conductor of heat and
electricity
Transition Metals
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Elements in groups 312
Less reactive harder
metals
Includes metals used
in jewelry and
construction.
Metals used “as
metal.”
Carbon Family
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Elements in group 14
Contains elements
important to life and
computers.
Carbon is the basis
for an entire branch
of chemistry.
Silicon and
Germanium are
important
semiconductors.
Nitrogen Family
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Elements in group 15
Nitrogen makes up
over ¾ of the
atmosphere.
Nitrogen and
phosphorus are both
important in living
things.
Most of the world’s
nitrogen is not
available to living
things.
The red stuff on the
tip of matches is
phosphorus.
Oxygen Family or Chalcogens
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Elements in group 16
Oxygen is necessary
for respiration.
Many things that stink,
contain sulfur (rotten
eggs, garlic,
skunks,etc.)
Halogens
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Elements in group 17
Very reactive, volatile,
diatomic, nonmetals
Always found
combined with other
element in nature .
Used as disinfectants
and to strengthen
teeth.
GROUPS OF ELEMENTS IN
PERIODIC TABLE
NONMETALS
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Second most amount of elements.
Elements found to the right of the
heavy black line on periodic table.
Properties that most nonmetals
exhibit:
soft, does not conduct electricity
and does not have a luster
GROUPS OF ELEMENTS IN
PERIODIC TABLE
METALLOIDS
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Elements that straddle the heavy
black line
Combination of metallic and
nonmetallic properties.
GROUPS OF ELEMENTS IN
PERIODIC TABLE
NOBLE GASES
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Elements found in group 18.
Extremely unreactive
elements.
The Noble Gases
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Elements in group 18
VERY unreactive,
monatomic gases
Used in lighted “neon”
signs
Used in blimps to fix
the Hindenberg
problem.
Have a full valence
shell.
Reading the Periodic Table of Elements
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PLEASE TAKE OUT YOUR PERIODIC TABLE
The largest number (with decimal) is the
Atomic Mass # and is the weight of the atom
and how many (+) and (n) are in the nucleus
The smaller number (no decimal) is the Atomic
# and is the number of (+) or (-). REMEMBER
the number of (+) and (-) should always be
equal.
The Symbol represents the Latin name of the
chemical and is used within equations.
Please memorize the ELEMENTS that were
given to you!
PRACTICE, PRACTICE, PRACTICE
Answer the following questions about Calcium:
# of (-)
# of (+)
# of (n)
Atomic #
Atomic Mass #
Symbol
ANSWERS
Answer the following questions about Calcium:
# of (-)
# of (+)
# of (n)
Atomic #
Atomic Mass #
Symbol
20
20
20
20
40.06
Ca
LET’S DO IT AGAIN… 
Answer the following questions about Aluminum:
# of (-)
# of (+)
# of (n)
Atomic #
Atomic Mass #
Symbol
ANSWERS
Answer the following questions about Aluminum:
# of (-)
# of (+)
# of (n)
Atomic #
Atomic Mass #
Symbol
13
13
14
13
26.98…
Al
Atomic Structure
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Protons, neutrons and
electrons are known as
(subatomic particles)
 All of the mass of an atom is
found in the nucleus
 Particles in the nucleus are
called nucleons
Atomic Structure Continued
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Two types of nucleons
 A. Protons – discovered by
Rutherford
 1. Positively charged (+) particles
 2. number of protons = atomic
number of element
 3. The number of protons in an
atom determines the type of
element it will be.
Atomic Structure Continued
B.
Neutrons – discovered by
Chadwick
 1. neutral particle (no
charge)
 2. amount of neutrons in
an element = take the
atomic mass and subtract
the atomic number
Atomic Structure cont…
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C. Electrons – discovered by
JJ Thomson
 1. Negatively charged (-)
particle
 2. Outside of the nucleus
 3. Electrons found in a cloud
around the nucleus
 4. The electron cloud is
called an orbital or shell
EXAMPLES OF TABLES
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Remember that every author has a
different way of recognizing the
families and placing the numbers
regarding each of the elements in a
different location.
Learn how to read every periodic table
Select an element
(
= Internet link )