The class will be divided
into three groups. Each
group will received a
puzzle and a code to be
solved.
A
2
H
1
O
23
V
3
B
5
I
4
P
18
W
7
C
6
J
14
Q
19
X
16
D
13
K
9
R
21
Y
26
E
11
L
17
S
24
Z
20
F
10
M
8
T
27
G
22
N
25
U
1
Have you ever
wondered what
everything around
you is made of?
400 BC
People back then
thought that if you are
going to cut something,
an apple for instance,
you could just keep on
cutting it forever and
ever, that there is no
end to smallness.
DEMOCRITUS
He insisted that at some
point you would reach
particles so small and
indestructible they could
not be divided any further.
He called this small particle
, “atomos” which means
indivisible.
OBJECTIVES:
1.Define what is an atom.
2.Identify and describe the
subatomic particles of an atom.
What is an
ATOM?
butter
flour
eggs
Chocolate
chips
sugar
ATOMS
"atom" is derived from the Greek word,
“atomos” or indivisible.
Are the building blocks of matter that
make up everything that exists in our
world.
Smallest unit of matter.
Atoms are so small that…
it would take a stack of about
50,000 aluminum atoms to equal
the thickness of a sheet of
aluminum foil from your kitchen.
www.deckersfoods.com
a human hair is about 1
million carbon atoms wide.
Atoms are so small that…
150-pound human body contains
about 6.5 octillion atoms!
The most abundant type of
atom in the universe is the
hydrogen atom. Nearly 74% of
the atoms in the Milky Way
galaxy are hydrogen atoms.
Subatomic particles
PROTON
ELECTRON
NEUTRON
ATOM
The nucleus, which is found at the
center of the atom contains protons
(positively charged) and neutrons (no
charge). The outermost regions of the
atom contain the electrons (negatively
charged).
electron
nucleus
orbit
proton
neutron
Properties of the subatomic particles
CHARGE
positive (+)
MASS IN Location in the
grams
Atom
1.678x10^Inside the
24
nucleus
neutral
1.678x10^24
Inside the
nucleus
negative (-)
9.109x10^28
Outside the
nucleus
PROTON
 Help make up the nucleus of the atom
 Help identify the atom (could be considered an
atom’s DNA)
 Equal to the atomic number of the atom
 Contribute to the atomic mass
 Equal to the number of electrons
ELECTRON
 Found outside the nucleus of the atom, in the
electron orbits/levels; each orbit/level can hold
a maximum number of electrons.
 Move so rapidly around the nucleus that they
create an electron cloud
 Mass is insignificant when compared to protons
and neutrons
 Equal to the number of protons
NEUTRON
 Neutral particles; have no electric
charge
 Help make up the nucleus of the atom
 Contribute to the atomic mass
Hydrogen (H) Atom
=1
=0
=1
• Notice the one
electron in the first
orbital
How many more electrons
can fit in the 1st orbital/
level?
Oxygen (O) Atom
=8
=8
=8
• Notice the two
electrons in the
first
orbital/level
and the six in
the second
How many more electrons
can fit in the 2nd orbital/ level?
Sodium (Na) Atom
=11
=12
=11
• Notice the
two electrons
in the first
orbital/level,
eight in the
second, and
one in the
third orbit.
How many more electrons
can fit in the 3rd orbital/ level?
Why do we
need to study
atoms?
SUMMARY
"atom" is derived from the Greek word,
“atomos” or indivisible.
Atom is the smallest unit of matter. It is so
small it cannot be seen with naked eyes.
Atom has three subatomic particles called
electron, proton and neutron.
Proton has positive electrical charge and is
located inside the nucleus. It contributes to
the atomic mass.
Electron has negative electrical charge and is
located outside the nucleus. It is equal to the
number protons in an atom.
Neutron has no electrical charge as it is a
neutral component of an atom. It is located
inside the nucleus.
LET’S CHECK
WHAT YOU
HAVE
LEARNED!
1. ______________ is the smallest
unit of matter.
ATOM
1. ______________ is the smallest
unit of matter.
1. Proton has ______________
electrical charge and is located
inside the nucleus.
POSITIVE
2. Proton has ______________
electrical charge and is located
inside the nucleus.
3. ______________ has no
electrical charge and is also
located inside the nucleus.
NEUTRON
3. ______________ has no
electrical charge and is also
located inside the nucleus.
4. Who proposed the idea of an
indivisible small particle called
“atomos”?
4. Who proposed the idea of an
indivisible small particle called
“atomos”?
DEMOCRITUS
6. TRUE OR FALSE.
The electrons help make up the nucleus of
the atom.
6. TRUE OR FALSE.
The electrons help make up the nucleus of
the atom.
FALSE
7. TRUE OR FALSE.
The inner shell of an atom can only hold
two (2) electrons.
TRUE
10.
8.
11.
9.
12.
GREAT
JOB!