Download THE ATOM Atoms are much too small for us to see

THE ATOM
Atoms are much too small for us to see. In order to imagine what they
look like, we use a model that looks quite similar to a tiny solar system.
We call the center (the sun of the solar system) the ru,Acieus
Circling around the nucleus are electrons (the planets in the solar sytem).
All atoms are made up of three parts:
voi-tfen p+)
Protons (SOMdi
charge
- Have a posIiive
- Are located in the nucleus
- Have a mass of one atomic mass unit
Neutrons (Some+irnes vierki-en r‘e
- Have a neutra.
charge
- Are located in the nucleus
- Have a mass of one atomic mass unit
NE
T ON;
TH
PROTON;
LARGE yITH
PO I IVE CHARGE
SMALL
NEGATIVE CA 't
)
Electrons (sometimes vir
charge
- Have a nayetive
- Circle the nucleus in shells
- Have so little mass that we consider them to weigh nothing
Electrons circle the nucleus in energy levels or sheitS
. You can
think of them like rows at a concert - each row or shell has a certain
number of seats. The electrons will fill the seats in the first row, but
once that row is full they have to move to the second row. Then they
fill that row, and so on.
1st Shell
ed shell
1<
3rd Shell
tt
4th Shell
N
2 electrons
8 electrons
8 electrons
16 electrons
Atomic Number
An atom (at least the kind we talk about this year) always has the
same number of positive charges and negative charges, so the overall
. This means it has the same number of
charge is zero
protons
and et-ectrons
. We call this the
of an atom. Every different
atomi c
numbertype of atom has a different atomic number. This is how the elements
are arranged on the periodic table.
Atomic Number = Number of protons OR Number of electrons
Atomic Mass
Protons and neutrons are about the same size and the have about
the same mass. We randomly chose a unit to represent the mass of one
MaeS
proton and called it an Qi-omic
Electrons are so tiny that we consider them to weigh nothing. Think of
it like standing on a scale and then dropping some salt on your hand. The
salt is so small compared to you, it will not change the mass on the scale.
So all of the mass from an atom comes from the protons and the
neutrons. If we add together the number of protons and the number of
neutrons, we get the cd0rnic MaSS of the atom.
Atomic Mass = # of protons + # of neutrons
So what does this all mean?
The Periodic Table
The periodic table tells us the atomic number and the atomic mass
of each element, so we can figure out how many protons, electrons, and
neutrons it has, and what it will look like.
The Atoms Family
Atomic Math Challenge
8
0
Oxygen
15.999
..bie note:
8
-44—
Name
A-Vomic 14 umber
Element 5rbol
-41— &muck Name
-411— Morn'tc Moss
Atomic number equals
the number of
P+
or C
Atomic mass equals
pt
the number of
+
o
n
usucxuI.j ro LA n Ckt, CI to '-ifrle nearesf
whoke number, because Vie cari+ Irla102 a decimal.
number cri netxt-rons.
30
3
A+OrY11C MCISS
.IS
o
Li
Zinc
15.999
65.39
Atomic # =
Atomic Mass =
# of Protons =
# of Neutrons =
# of Electrons =
Atomic # =
Atomic Mass =
# of Protons =
# of Neutrons =
# of Electrons =
14
5
6.941
Atomic # =
Atomic Mass =
# of Protons =
# of Neutrons =
# of Electrons =
35
B
Bromine
Silicon
28.086
Atomic # =
Atomic Mass =
# of Protons =
# of Neutrons =
# of Electrons =
10.81
Atomic # =
Atomic Mass =
# of Protons =
# of Neutrons =
# of Electrons =
79.904
Atomic # =
Atomic Mass =
# of Protons =
# of Neutrons =
# of Electrons =
16
53
25
Mn
Iodine
32.06
Atomic # =
Atomic Mass =
# of Protons =
# of Neutrons =
# of Electrons =
12
126.905
Atomic # =
Atomic Mass =
# of Protons =
# of Neutrons =
# of Electrons =
18
54.938
Atomic # =
Atomic Mass =
# of Protons =
# of Neutrons =
# of Electrons =
19
Mg
Argon
24.305
39.948
39.098
Atomic # =
Atomic Mass =
# of Protons =
# of Neutrons =
# of Electrons =
Atomic # =
Atomic Mass =
# of Protons =
# of Neutrons =
# of Electrons =
Atomic # =
Atomic Mass =
# of Protons =
# of Neutrons =
# of Electrons =
79
1
Fluorine
Gold
196.967
Atomic # =
Atomic Mass =
# of Protons =
# of Neutrons =
# of Electrons =
9
1.008
18.998
Atomic # =
Atomic Mass =
# of Protons =
# of Neutrons =
# of Electrons =
Atomic #
Atomic Mass =
# of Protons =
# of Neutrons =
# of Electrons =