Download atomic number

21
Atom
September 23
Warm - Up:
proton, neutron
Reminders:
Today:
1. Check Density HW
2. Notes: Atoms
3. Study Guides
Six Weeks Test Thursday
36. proton
positively charged subatomic particle found in
nucleus of an atom
Draw it:
Connect it:
found in nucleus
heavy, 1 amu
2
37 . neutron
neutral subatomic particle found in nucleus
of an atom
Draw it:
Connect it:
no charge
heavy, 1 amu
3
HELIUM ATOM
Shell
proton
electron
+
N
N
+
-
neutron
Notice the location of each particle!!!
Let’s Explore some Models of Atoms...
Activity:
Observe the “petri dish” model of an atom.
Draw what you see and write at least three
observations.
Complete the chart & Questions.
Petri Dish Atom Model
+
+
+
6
Notes: Parts of an Atom
There are two main regions within an atom:
NUCLEUS
-the
is located in the center of
the atom and contains the protons and the neutrons
(it is the denser part because it has the larger massive
particles)
ELECTRON
-the
cloud that surrounds the
nucleus and contains electrons, makes up most of the
volume of atom, it is 100, 000 times bigger than
nucleus)
Atoms are made up of three main
subatomic particles:
PROTONS have a positive (+) charge and
are located in the nucleus.
NEUTRONS have no charge and are
located in the nucleus.
ELECTRONS have a negative (-) charge
and are located outside the nucleus.
In any NEUTRAL atom, three
things are equal---- atomic number,
number of electrons, & number of
protons
To remember this, think of the word APE :
Atomic #
All three are equal. If
Protons
you know one, you
Electrons
know the other two.
Determining the Identity of an
Element
Each element on the Periodic Table is made of only
one kind of atom. The number of protons
determines an element’s IDENTITY. The
number of protons is represented by the
ATOMIC NUMBER.
If you interpret the the
information on the Periodic Table, you can find the
number of subatomic particles in an atom of a given
element.
Atomic
number
element
name
6
C
Carbon
12.011
element
symbol
atomic
mass
To find the neutrons in the nucleus
remember MAN :
Mass number - Atomic # = Neutrons
To find the subatomic
particles of any atom
remember the mneumonic:
APE MAN
ATOMIC STRUCTURE
Draw this chart on the back of your notes.
Particle
Charge
Mass
proton
+ charge
1
neutron
No charge
1
electron
- charge
0
What makes a Hydrogen atom different
from a Helium atom?
Hydrogen
helium
ATOMIC STRUCTURE
Did you notice that…
Electrons are arranged in Energy Levels or Shells
around the nucleus of an atom.
32
8
P+
n
2
8
18
HELIUM ATOM
Shell
proton
+
electron
N
N
+
-
neutron
Notice the location of each particle!!!
ATOMIC STRUCTURE
2
He
4
Atomic number
the number of protons in an atom
Atomic mass
the number of protons and
neutrons in an atom
ALL atoms are NEUTRAL!!!! Therefore,
# of electrons = # of protons
ATOMIC STRUCTURE RULES!!!
•
•
•
•
•
The Atomic Number = # of protons in the nucleus.
The Atomic Mass = # of Protons + Neutrons
The number of Protons = Number of Electrons.
Electrons orbit the nucleus in energy levels or
electron shells.
Each shell can only carry a set number of electrons.
2, 8, 8, 18, 32
Making a Model of the Atom
Electrons
NUCLEUS
Protons
Neutrons
HYDROGEN
1 e___
1 P+
___
0 n
___
P = __
e = __
N = __
HELIUM
2 e___
2 P+
___
2 n
___
P = __
e = __
N = __
LITHIUM
3 e___
3 P+
___
4 n
___
P = __
e = __
N = __
BERYLLIUM
4
___
e4
___
P+
5 n
___
P = __
e = __
N = __
BORON
5 e___
5 P+
___
6 n
___
P = __
e = __
N = __
CARBON
6 e___
6 P+
___
6 n
___
P = __
e = __
N = __
Now Use the White Board to
draw the following atoms…
NITROGEN
7 e___
7 P+
___
7 n
___
P = __
e = __
N = __
CHLORINE
___ e ___ P +
___ n
P = __
e = __
N = __
Complete the Chlorine atom on
your own.
Fe2O3
chemical formula
1.There are ___ elements in the formula.
2. There are ___ atoms in the formula.
32