Atoms
You will need:
I. The vocab cards for
Atom, nucleus, electron, element, isotope,
compound , ionic bond, ion, covalent bond, molecule,
van der Waals forces.
2. 2 Pieces of paper
3. A baggie with 3 colors of holes.
Write the number on the baggie here__________
Atomic Particles
I. Protons – positive; determines the element;
A. power of Atomic bomb
B. (fission); Hydrogen bomb (fusion)
II. Neutron – neutral; determines the isotope
III. Electron – negative; determines the charge; power
of electricity
Size
I. Nucleus: Protons + neutrons
A. Protons = neutrons in size
II. Orbitals – electrons
III. Protons = electrons in charge,
A. electron size – tiny
Determining the number of protons, neutrons,
and electrons.
I. Protons – is the atomic number
II. Electrons – is the atomic number
III. Neutrons –
A. Round the atomic mass number to the nearest
ones.
B. Subtract the number of protons from the atomic
mass
Periodic
Table
O
Atomic Mass =
Protons + Neutrons
8
Oxygen
15.994
Atomic number = # of
protons, # of electrons
symbol
Element Name
On each piece of paper, please draw the circle
below. Fill the paper with the drawing.
Please make each ring a different color.
Color in the center circle ONLY –
use the same color as the line.
Used the punched holes to show oxygen on your
drawing. For now, put the electrons anywhere on
the outer 3 rings
Example: Oxygen
Protons: 8
Electrons: 8
Neutrons: 16 – 8 = 8 (not all elements will have
the same number of neutrons as
protons)
Use blue for protons, green for neutrons,
and orange for electrons.
Practice: build the following atoms on your
drawing.
Lithium – Li
Aluminum – Al
Sodium – Na
Potassium – K
Chlorine - Cl
Arranging the electrons
Note: This is a very simplified arrangement. You will get
a more accurate one in chemistry.
2 electrons fit in the 1st (inner) level.
8 electrons fit in the 2nd level.
8 electrons fit in the 3rd level.
Please draw in where the electrons will go.
Now build the atoms with the electrons in the
correct level.
Lithium – Li
Aluminum – Al
Sodium – Na
Potassium – K
Chlorine - Cl
Isotopes
I. All of the atoms of the same elements
HAVE THE SAME # OF PROTONS
II. An isotope has a different number of NEUTRONS
THAT THE MOST COMMON.
A. The most common is the number of neutrons in
the atom that has the atomic mass rounded to the
1s.
Use the electrons to fill the orbitals starting from the
inside.
EX: Hydrogen – Protons-1 so electrons- 1
Since Hydrogen has one electron in its outermost
shell it has a dot structure of
H
Example: Lithium
3 electrons
Since lithium has 1 electron in the outermost shell its
dot structure is
Li
Example: Nitrogen
7 electrons
Since nitrogen has 5 electron in the outermost shell its
dot structure is

 N
Example: Aluminum - 13 electrons
Since aluminum has 3 electron in the outermost shell

its dot structure is
Al
The electrons in the outer most shell
determines how the element will react.
Atoms want to be “happy”.
I. A happy atom has a full outer shell
A. It can LOSE electrons and become more +
1. Li· has 1 electron so it will lose the 1 and
become Li+ (do not write a “1”).
B. It can GAIN electrons and become more –
1.
Oxygen has 6 electrons so will add 2
electrons so will become 2-, O2-.
st column have 1 electron in the outer shell and so
The
elements
in
the
1
This can be predicted from the Periodic Table. The column
will
lose 1shows
electron
and
give those
elements a in
charge
1+ (but the 1 is
number
the
number
of electrons
eachofelement’s
not
written).shell.
outermost
+
The elements in the 2nd column have 2 electron in the outer shell and so
will lose 2 electrons and give those elements a charge of 2+.
2+
The elements in the 7th column have 7 electron in the outer shell and so
will GAIN 1 electron and give those elements a charge of 1-.
-
The elements in the 6th column have 6 electron in the outer shell and so
will gain 2 electrons and give those elements a charge of 2-.
2-
The elements in the 5th column have 5 electron in the outer shell and so
will gain 3 electrons and have a charge of 3-.
3-
The elements in the 4th column have 4 electrons in the outer shell and
so could gain or lose 4 electrons. This is so many that elements in this
column share electrons rather than give or take electrons.
4+
4-