Atoms
The smallest particle of an
element that still has properties
of that element
Example – Gold only contains
gold atoms.
https://www.youtube.com/watch?v=cnXV7Ph3WPk
Atoms Contain Three
Particles:
Protons (p+)
1. Positively charged
particles
2. In a neutral atom,
equals the number of
electrons
3. Has more mass
than an electron
4. Found in the
nucleus of an atom
Electrons (e-)
Neutrons (n0)
1. Negatively
1. Neutral or no
charged particles
charge particles
2. In a neutral atom,
equals the number of
protons.
3. Barely has mass 2. Has the same
4. Not found in the mass as a proton
nucleus of an atom, 3. Found in the
but found in energy nucleus of an atom
levels
How to determine the
number of protons,
neutrons, and electrons Atomic
Number – Tells
you the number of
protons in an
atom.
Element
Name
1
H
Hydrogen
1
Element Symbol
Atomic Mass –
Tells you the
number of protons
and neutrons in an
atom.
You already know
. . .
B
Find: ___________________
Element Name: ___________
Boron
5
Atomic Number: __________
11
Atomic Mass: _____________
So Lets Add On B
Find: ___________________
Boron
Element Name: ___________
Number of Protons
=
5
Atomic
Number:
__________
Atomic Number
11
Atomic Mass: _____________
The number of neutrons =
In aMass
neutral
atom –Number
the
Atomic
– Atomic
# number
of
Protons:
_____________
5
of protons equals
the number
of electrons.
5
# of
Electrons:
____________
# of Neutrons: ____________
6
Practice:
Br
Find: ___________________
Bromine
Element Name: ___________
35
Atomic Number: __________
80
Atomic Mass: _____________
# of Protons: _____________
35
# of Electrons: ____________
35
45
# of Neutrons: ____________
Practice:
1.Mg
2.Si
3.K
4.Pb
The Atom
Energy
Levels
Nucleus
P+
N0
Octet Rule –
Energy Level 1 – 2 eEnergy Level 2 – 8eEnergy Level 3 – 18e-
Li
Find: ___________________
Lithium
Element Name: ___________
3
Atomic Number: __________
7
Atomic Mass: _____________
3
# of Protons: _____________
3
# of Electrons: ____________
4
# of Neutrons: ____________
Drawing Atoms
X
X
P+ 3
N0 4
X
Ne
Find: ___________________
Neon
Element Name: ___________
10
Atomic Number: __________
20
Atomic Mass: _____________
10
# of Protons: _____________
10
# of Electrons: ____________
10
# of Neutrons: ____________
XX
X
X
X
P+ 10
N0
10
X
XX
X
X