
The middle of an atom, called the nucleus,
has a _________ electrical charge, while the
particles that circle the outside of the nucleus
have a ____________ charge.
a. Positive, neutral
b. Neutral, positive
c. Negative, positive
d. Positive, negative


So…..atoms are made up of negative protons,
neutral neutrons, and positive circling
electrons…. right?
Wrong!!
Every same type of atom has the same # of
______________________


Ex. On P.O.E.
Atomic #- is the number of
protons an atom has!




Vocab:
Atomic mass= is equal to its # neutrons plus #
protons.
Can’t measure with scale so unit is not grams but
in amu
The mass of this oxygen atom is….?
 16! Because
 8 protons +8 neutrons=16
 Weight of protons=weight of neutrons
Atomic
mass= p+n

The electron is so small it is not even counted
as part of its atomic mass/mass number!

The atom found most frequently in nature
A neutral atom has the same number of
electrons as protons

So what is this_________>







Vocab:
Ion= Is any atom that has a different number
of electrons than protons.
If you take away an electron from an atom
It becomes positively charged.
If you add an electron to an atom
it becomes negatively charged.
Now a positive ion
+
Now a negative
ion
-

And so……if hydrogen has an atomic number

Then it is called an isotope!
of 1, it must have 1 proton. But what if it
has 2 neutrons?
Vocab:
Isotope: An atom/element with a different
number of neutrons than protons

Okay…what if the number of p+ and neutrons
are the same, but we have a different number of
electrons. Then the atom is called an ……
ION
plate # of
# of
#
particle proto
s
ns
1
2
3
4
5
6
7
#of
neutr
ons
# of
electr
ons
Atomic Atomi Isotope,
#
c
Ion,
mass Neutral?
Name of
Atom
1.
2.
3.
4.
5.
6.
What two numbers do you see that are
always the same?
Can an atom be both an ion and an isotope?
What do you think would happen if a
common atom lost 3 electrons?
_________+____________=atomic mass
What is the smallest sub atomic particle in
the atom?
What is a limitation to using this type of
model?
Every same type of atom has the same # of
______________________


Ex. On P.O.E.
Atomic #- is the number of
protons an atom has!
Atomic
mass= p+n
Now a positive ion
+
Now a negative
ion
-
Vocab:
Isotope: An atom/element with a different
number of neutrons than protons

Okay…what if the number of p+ and neutrons
are the same, but we have a different number of
electrons. Then the atom is called an ……
ION



http://www.chemicalelements.com/bohr/b00
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http://library.thinkquest.org/J002959F/_bord
ers/oxygen8.jpg
http://library.thinkquest.org/J002959F/_bord
ers/oxygen8.jpg
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ball_IMGP2300.gif