Introduction to Atoms and Atomic Particles

Contributed by:
Jonathan James
This ppt gives information about:
1. Atoms
2. Subatomic particles- Electrons, Protons, Neutrons
3. Atomic number, Mass number, Atomic mass
4. Ions
1. - -
-
++ +
- + + + -
+ +
-
- -
2. SPS1. Obtain, evaluate, and
communicate information from the
Periodic Table to explain the relative
properties of elements based on
patterns of atomic structure.
a. Develop and use models to compare
and contrast the structure of atoms,
ions and isotopes.
(Clarification statement: Properties
include atomic number, atomic mass
and the location and charge of
subatomic particles.)
3. • What are the different subatomic
particles of an atom?
• What are the locations, charges, and
weights/masses of each subatomic
particle?
• How do the subatomic particles of an
atom affect its characteristics?
4. • How do you find the number of
protons, neutrons, and
electrons in an atom?
• What is the difference between
an ion, an isotope, and a
“normal” atom?
5. • You should know the different
subatomic particles
• You should know the charges,
locations, and masses/weights of
each subatomic particle
6. • If you change the number of
electrons, you have an _____.
• If you change the number of
neutrons, you have an _____.
• If you change the number of
protons, you have a different
element.
7. • Anything that has mass and takes up
space (volume)
– Examples:
• A brick has mass and takes up space
• A desk has mass and takes up space
• A pencil has mass and takes up space
• Air has mass and takes up space
All of the above examples are considered matter because
they have mass and take up space. Can you think of anything
that would not be considered matter?
8. • Smallest possible unit
into which matter can
be divided, while still
- maintaining its
properties.
+ • Made up of:
+
++ - – protons +
– neutrons
– electrons -
• The solar system is
- commonly used as an
analogy to describe the
structure of an atom
9. • it would take a stack of about
50,000 aluminum atoms to equal
the thickness of a sheet of
aluminum foil from your kitchen.
• if you could enlarge a penny until
www.deckersfoods.com
it was as wide as the US, each
of its atoms would be only about
3 cm in diameter – about the
size of a ping-pong ball
• a human hair is about 1 million
carbon atoms wide. C-C-C-C-C-… + 999,995 more
• a typical human cell contains
roughly 1 trillion atoms. 1 trillion atoms 
• a speck of dust might contain
3x1012 (3 trillion) atoms. .
Is made of approximately 3 trillion atoms
• it would take you around 500
years to count the number of
atoms in a grain of salt.
Just one of these grains
10. In order to try to gain an idea of how small an
atom really is, you will complete the following
activity.
1. Cut a strip of 11 in. paper in half.
2. Discard one half.
3. Cut the remaining piece in half.
4. Continue cutting and discarding the strips as many
times as you can.
5. Make all cuts parallel to the first one. When the
width gets longer than the length, you may cut off
the excess, but that does not count as a cut.
11. • How many cuts were you able to
make?
• Do you think you could keep cutting
the paper forever? Why or why not?
You would have to cut the paper in
half around thirty-one (31) times to
get to the size of any atom.
http://www.miamisci.org/af/sln/phantom/papercutting.html
12. • Positively (+) charged - -
particles -
• Help make up the ++ +
- + + + -
nucleus of the atom + +
• Help identify the atom -
(could be considered an - -
atom’s DNA)
• Equal to the atomic
number of the atom
• Contribute to the
atomic mass
• Also Equal to the +
number of electrons
13. - -
-
• Neutral particles;
++ +
- + + + - have no electric
+ + charge
-
- - • Help make up the
nucleus of the
atom
• Contribute to the
atomic mass
14. • Negatively (-) charged - -
particles -
• Found outside the nucleus of
the atom, in the electron ++ +
- + + + -
orbits/levels; each orbit/level + +
can hold a maximum number of
electrons ( 1st = 2, 2nd = 8, 3rd = 8 or -
18, etc…)
- -
• Move so rapidly around the
nucleus that they create an
electron cloud
• Mass is insignificant when
compared to protons and
neutrons
• Equal to the number of
-
protons (in a neutral atom)
• Involved in the formation of
chemical bonds
15. • Protons and neutrons are grouped together to
form the “center” or nucleus of an atom.
Notice that the electrons are not apart of the nucleus
-
-
+
+ +
-
16. • Particles that make up protons and neutrons
Notice the Notice the
smaller smaller
particles particles
that make
up this
neutron
after you
+ that make
up this
proton
after you
take a take a
closer look. closer look.
What do you notice about the number
of quarks in the neutron and proton?
17. Neutron = 1.6749286 x10-27 kg
Proton = 1.6726231 x10-27 kg
Electron = 9.1093897 x10-31 kg
+
- -
- - - -
- - - - - -
- - - - - - - - - -
- - - - - - - - - - - - - -
1839 electrons = 1 neutron 1836 electrons = 1 proton
+
How do you think the mass of a neutron
compares to that of a proton?
1 neutron ≈ 1 proton
18. Size in Size in - -
atoms meters
(m) -
Atom 1 10-10
++ +
Nucleus __1__
10,000
10-14 - + + + -
Proton or ___1___
100,000
10-15 + +
Neutron
Electron _____1____ 10-18
-
100,000,000
or Quark (at largest)
- -
19. • The number of protons in the nucleus of an atom
-
What would
be the atomic
+ number of this
++
-
-
atom?
20. • The total number of protons and neutrons in an atom’s nucleus
• Expressed in Atomic Mass Units (amu)
– Each proton or neutron has a mass of 1 amu
What would be the mass
number of this atom? -
+  3
 4
+
++
-
3 protons + 4 neutrons =
a mass number of 7 amu
Why did we not account for the -
electrons when calculating the
mass number?
21. Atom Builder
• Using the interactive
website link below,
practice building atoms.
• http://www.pbs.org/wgbh/
aso/tryit/atom/
• Using the classzone.com link
below, click on the “Build an
Atom” simulation and practice
building atoms.
http://www.classzone.com/books/ml_sci_physical/
page_build.cfm?id=resour_ch1&u=2##
22. • Atoms that have the same number of protons,
but have different numbers of neutrons
• Examples Notice that each of these atoms have one proton;
therefore they are all types of hydrogen. They
just have a different mass number (# of neutrons).
-
-
+ + +
-
Hydrogen (Protium) Hydrogen (Deuterium) Hydrogen (Tritium)
23. • The weighted average of the masses of all the naturally occurring isotopes
of an element
• The average considers the percent abundance of each isotope in nature
• Found on the periodic table of elements
• Example
What would be the atomic mass (≈) of Hydrogen if these three isotopes
were found in the following percentages (99.9, 0.015, 0) respectively?
-
+ +
+ -
-
Hydrogen (Protium) Hydrogen (Deuterium) Hydrogen (Tritium)
Mass # = 1 amu Mass # = 2 amu Mass # = 3 amu
If you simply average the three, 2 amu (1 amu + 2 amu + 3 amu/3) would be the atomic mass,
but since 99.9% of the Hydrogen is Protium, the atomic mass is around 1 amu (.999 x 1 amu)
24. • Charged particle
that typically
results from a loss - -
or gain of
-
electrons = 8
+
• Two types: = 8 ++ +
– Anion = negatively - + + + -
charged particle - =9
68
+ +
– Cation = positively
charged particle
- -
Now
Now that
that three
Currently,this
thisatom
electrons
atom ofof oxygen
were just
oxygen lost,
is -
gained
the number
an electron,
of electrons
it is no
(6)longer
and
-
neutral because it has an equal
number of or
protons
neutral (8) an
is atom.
still (8)
electrons unbalanced;
It is protons
and now
considered
therefore, anit is
ionstill
(anion).
(8).an ion,This
but ion
nowhas
it
ismore
specifically
electronsreferred
(9) thantoprotons
as a cation.
(8). Symbol
Symbol == O
O1-2+
25. Building Ions
Using the whiteboard and the proton, neutron, and
electron pieces, build the following ions, and
determine their atomic and mass numbers.
Ions Protons Neutrons Electrons
Carbon (C³¯) 6 6 9
Hydrogen (H¹+) 1 0 0
Oxygen (O²¯) 8 8 10
Lithium (Li³+) 3 4 0
Sodium (Na¹¯) 11 12 12
Be aware that the atomic and mass numbers are not
impacted by the loss or gain of electrons.