Chap 4 Bell -Ringers
The
Structure
of the Atom
The Atom has a
Structure
What we’ve seen so far…
Chapter 1
The Science of Chemistry
- Chemistry is about discovering
and understanding natural laws
using the scientific method
- Energy cannot be created nor
destroyed
What we’ve seen so far…
Chapter 1
The Science of Chemistry
Chapter 2
Matter and Atoms
- Matter can be mixtures or
substances. The smallest unit of a
pure substance is an element.
- Each element is a type of atom,
and they can be arranged in a
periodic table.
- Atoms come together to form
compounds. Atoms with an electric
charge are known as ions.
What we’ve seen so far…
Chapter 1
The Science of Chemistry
Chapter 2
Matter and Atoms
Chapter 3
Temperature, Energy, and Heat
- Temperature is a measure of
kinetic energy.
- Heat is thermal energy.
- Heat gain and heat loss can cause
phase changes, as molecules are
rearranged.
What we’ve seen so far…
Chapter 1
The Science of Chemistry
Chapter 2
Matter and Atoms
Temperature, Energy, and Heat
Physical and Chemical Change
- In a physical change molecules
are rearranged. In a chemical
change atoms are rearranged to
make new substances.
- Chemical reactions can be
endothermic or exothermic.
- Many reactions occur in aqueous
solution, and some elements are
more reactive than others.
Chapter 1
The Science of Chemistry
Chapter 2
Matter and Atoms
Temperature, Energy, and Heat
Physical and Chemical Change
How can we explain the
properties and behaviors
observed so far?
Chapter 1
Answers can
be found inside
the atom
The Science of Chemistry
Chapter 2
Matter and Atoms
Chapter 3
Temperature, Energy, and Heat
Physical and Chemical Change
How can we explain the
properties and behaviors
observed so far?
92 different types of atoms!
Atoms are made from smaller particles!
protons
neutrons
electrons
Each of the elements is a unique type of atom.
Atoms are made from smaller particles!
protons
neutrons
electrons
How did scientists come up with this?
It started a long time ago…
460 – 370 BC
Today
Democritus
Beginning of Atomism
You cannot divide something in half forever.
The smallest piece of matter is called an atom.
How do you find out about
something you can’t see?
Think of the conservation of mass labs,
distilled wood, even flame test lab
Think of experimentation of the
Copper, HCl and Zinc lab
Think of the Rutherford
marble tossing lab
Bellringer
When scientists wanted to find out what an
atom was, they were not able to look directly
at what the atom was made of. They had to
make inferences from the results of many
different experiments. It was like trying to
describe a picture, such as the one on the
next slide, with only small portions visible.
Bellringer, continued
1. Write four sentences describing what
you can see of the above picture.
2. What information or parts of the picture
would make
your descriptions more accurate
without revealing the entire picture?
Scientists contributing
CHADWICK
THOMSON
RUTHERFORD
DALTON
de BROGLIE
BOHR
Dalton’s Postulates
460 – 370 BC
1808
Democritus
Atomism
Over 2,000 years later
John Dalton comes up
with the first “modern”
atomic theory.
Today
1. All elements are made of tiny indivisible
particles called atoms.
Dalton’s Postulates
460 – 370 BC
1808
Democritus
Atomism
Today
1. All elements are made of tiny indivisible
particles called atoms.
2. All atoms of the same element are
the same, but different from atoms of
every other element.
Over 2,000 years later
John Dalton comes up
with the first “modern”
atomic theory.
Dalton’s Postulates
460 – 370 BC
1808
Democritus
Atomism
Today
1. All elements are made of tiny indivisible
particles called atoms.
2. All atoms of the same element are
the same, but different from atoms of
every other element.
Over 2,000 years later
John Dalton comes up
with the first “modern”
atomic theory.
3. Chemical reactions rearrange atoms
but do not create, destroy, or convert atoms
from one element to another.
Dalton’s Postulates
460 – 370 BC
1808
Democritus
Atomism
Today
1. All elements are made of tiny indivisible
particles called atoms.
2. All atoms of the same element are
the same, but different from atoms of
every other element.
Over 2,000 years later
John Dalton comes up
with the first “modern”
atomic theory.
3. Chemical reactions rearrange atoms
but do not create, destroy, or convert atoms
from one element to another.
4.
Compounds are made from combining
atoms in simple whole number ratios.
Another kind of light?
460 – 370 BC
1808
Democritus
Atomism
Dalton
“Modern”
atomic theory
1870
Today
William Crookes invents a tube in
which virtually all the gas has been
removed.
Under high voltage, a ray was emitted
from the cathode end of the tube.
It started a long time ago…
460 – 370 BC
1808
Democritus
Atomism
Dalton
“Modern”
atomic theory
1870
Crookes
Cathode rays
Cathode rays
must be negative.
1897
J.J. Thomson
discovers the
electron
Today
It started a long time ago…
460 – 370 BC
1808
Democritus
Atomism
Dalton
“Modern”
atomic theory
1870
Crookes
Cathode rays
1897 1910
Thomson
Discovery
of the electron
Today
Ernest Rutherford
discovers the
nucleus
Size and mass
The size of the
atom comes
mostly from the
space occupied by
the electrons
The mass of the
atom comes mostly
from the nucleus
Charges in the atom
neutrons
protons
electrons
Charges in the atom
A complete
atom has a
charge of zero
Charges in the atom
neutrons
protons
electrons
What happens when you change the number of protons?
6 protons in
carbon
7 protons in
nitrogen
You obtain a different element!
The number of protons is also called
the atomic number for that element.
8 protons in
oxygen
The electron cloud
Electrons are very light and fast.
They are not organized along orbits around the nucleus.
Except for mass, virtually every property of atoms is
determined by electrons, including size and chemical bonding
neutrons
protons
electrons
What happens when you change the number of neutrons?
Atomic number
Neutrons act as “glue.”
They hold protons together in the nucleus.
Mass number = 6 p + 6 n = 12
12C
“carbon-12”
mass number: total number of protons and neutrons in a
nucleus.
Name
Mass
number
# protons
# neutrons
Name
Carbon-12
Mass
number
# protons
# neutrons
Carbon-13
Carbon-14
Name
Carbon-12
Carbon-13
Carbon-14
12
13
14
Mass
number
# protons
# neutrons
Name
Carbon-12
Carbon-13
Carbon-14
12
13
14
6
6
6
Mass
number
# protons
# neutrons
Carbon-12
Carbon-13
Carbon-14
12
13
14
# protons
6
6
6
# neutrons
6
7
8
Name
Mass
number
isotopes: atoms or elements that have the same number
of protons in the nucleus but different number of neutrons.
Two lithium isotopes in nature
Atomic mass
How can lithium
have 0.941
neutrons?
Number of neutrons for each of 100 lithium atoms randomly
sampled from nature
It’s an AVERAGE mass!
Isotope periodic table (first 4 rows)
Forces in the atom
There must be a
force that keeps the
nucleus together
Forces in the atom
In the nucleus
Electrons
The strong nuclear force attracts
protons to protons, neutrons to
neutrons, and protons to protons
Electrons repel each other, but don’t
“fall into” the nucleus because they are
in constant motion.
Electrons form bonds between atoms.
460 – 370 BC
1808
Democritus
Atomism
Dalton
“Modern”
atomic theory
1870
Crookes
Cathode rays
Today
1897 1910
Thomson
Discovery
of the electron
Rutherford
Discovery
of the nucleus
neutrons
protons
electrons
The size of the atom comes
mostly from the electrons
The mass of the atom comes
mostly from the nucleus
Who coined the term atom
in 4 BC?
Dalton
Democritus
Rutherford
Bohr
Thomson
100%
0%
om
so
B
oh
r
n
0%
Th
R
ut
he
rit
u
rfo
rd
s
0%
em
oc
D
al
to
n
0%
D
1.
2.
3.
4.
5.
Who stated that elements are
made of indivisible spheres called
atoms?
Dalton
Chadwick
Rutherford
Bohr
Thomson
100%
0%
om
so
Th
oh
r
n
0%
B
rfo
rd
0%
ut
he
R
C
ha
dw
ic
k
al
to
n
0%
D
1.
2.
3.
4.
5.
Who discovered the atom was
divisible and had subatomic parts?
Dalton
Chadwick
Rutherford
Bohr
Thomson
71%
14%
n
Th
om
so
r
oh
B
rfo
rd
ut
he
R
dw
ha
C
10%
0%
ic
k
al
to
n
5%
D
1.
2.
3.
4.
5.
Who discovered the electron?
Dalton
Chadwick
Rutherford
Bohr
Thomson
48%
30%
17%
4%
n
Th
om
so
r
oh
B
rfo
rd
ut
he
R
C
ha
dw
ic
k
al
to
n
0%
D
1.
2.
3.
4.
5.
Who discovered that atoms are
mostly empty space?
Dalton
Chadwick
Rutherford
Bohr
Thomson
96%
4%
n
0%
Th
om
so
r
oh
B
rfo
rd
0%
ut
he
R
C
ha
dw
ic
k
al
to
n
0%
D
1.
2.
3.
4.
5.
Who discovered the nucleus?
Dalton
Chadwick
Rutherford
Bohr
Thomson
100%
n
0%
Th
om
so
r
oh
B
ut
he
R
dw
ha
C
0%
rfo
rd
0%
ic
k
al
to
n
0%
D
1.
2.
3.
4.
5.
Who discovered the proton in the
nucleus?
Dalton
Chadwick
Rutherford
Bohr
Thomson
86%
9%
5%
n
0%
Th
om
so
r
oh
B
rfo
rd
ut
he
R
C
ha
dw
ic
k
al
to
n
0%
D
1.
2.
3.
4.
5.
Who stated that electrons are
located in fixed energy levels?
Dalton
Chadwick
Rutherford
Bohr
Thomson
62%
38%
n
om
so
oh
r
Th
ut
he
R
dw
ha
C
0%
B
rfo
rd
0%
ic
k
al
to
n
0%
D
1.
2.
3.
4.
5.
Who discovered the neutron?
Dalton
Chadwick
Rutherford
Bohr
Thomson
96%
n
0%
Th
om
so
r
oh
B
rfo
rd
ut
he
R
dw
ha
C
4%
0%
ic
k
al
to
n
0%
D
1.
2.
3.
4.
5.
Center of a atom, contains most
of the atom’s mass
Proton
Neutron
Electron
Nucleus
Energy levels
Mass number
Electromagnetic
force
91%
5%
0%
5%
0%
0%
0%
Pr
ot
on
N
eu
tro
n
El
ec
tr
on
N
uc
En
le
us
er
gy
le
M
ve
as
ls
s
nu
El
ec
m
tr
om ber
ag
ne
ti.
..
1.
2.
3.
4.
5.
6.
7.
Positively charged particle that
exists in the nucleus
of an atom.
Proton
Neutron
Electron
Nucleus
Energy levels
Mass number
Eelctromagnetic
force
96%
0%
0%
4%
0%
0%
0%
Pr
ot
on
N
eu
tro
n
El
ec
tr
on
N
uc
En
le
us
er
gy
le
M
ve
as
ls
s
nu
Ee
m
lc
tr
om ber
ag
ne
ti.
..
1.
2.
3.
4.
5.
6.
7.
Particle with no charge that
exists in the nucleus of an atom
Proton
Neutron
Electron
Nucleus
Energy levels
Mass number
Electromagnetic
force
96%
4%
0%
0%
0%
0%
0%
Pr
ot
on
N
eu
tro
n
El
ec
tr
on
N
uc
En
le
us
er
gy
le
M
ve
as
ls
s
nu
El
ec
m
tr
om ber
ag
ne
ti.
..
1.
2.
3.
4.
5.
6.
7.
The least massive of the three
subatomic particles which also
carries an negative net charge.
Proton
Neutron
Electron
Nucleus
Energy levels
Mass number
Electromagnetic
force
100%
0%
0%
0%
0%
0%
0%
Pr
ot
on
N
eu
tro
n
El
ec
tr
on
N
uc
En
le
us
er
gy
le
M
ve
as
ls
s
nu
El
ec
m
tr
om ber
ag
ne
ti.
..
1.
2.
3.
4.
5.
6.
7.
Describes how electrons are
arranged around an atom
Proton
Neutron
Electron
Nucleus
Energy levels
Mass number
Electromagnetic
force
96%
0%
0%
0%
0%
0%
4%
Pr
ot
on
N
eu
tro
n
El
ec
tr
on
N
uc
En
le
us
er
gy
le
M
ve
as
ls
s
nu
El
ec
m
tr
om ber
ag
ne
ti.
..
1.
2.
3.
4.
5.
6.
7.
82%
18%
0%
0%
0%
0%
0%
ro
n
El
ec
tr
on
Nu
cl
En
eu
er
s
gy
le
ve
M
El
as
ls
ec
s
tr
nu
om
m
ag
be
St
ne
r
ro
t
i
ng
c
f
o
nu
rc
e
cl
ea
rf
or
ce
on
0%
Ne
ut
Proton
Neutron
Electron
Nucleus
Energy levels
Mass number
Electromagnetic
force
8. Strong nuclear force
Pr
ot
1.
2.
3.
4.
5.
6.
7.
The force that holds the
positively charged nucleus
together is called
The force that holds the atom
together is called
88%
12%
0%
0%
0%
0%
0%
ro
n
El
ec
tr
on
Nu
cl
En
eu
er
s
gy
le
ve
M
El
as
ls
ec
s
tr
nu
om
m
ag
be
St
ne
r
ro
t
i
ng
c
f
o
nu
rc
e
cl
ea
rf
or
ce
on
0%
Ne
ut
Proton
Neutron
Electron
Nucleus
Energy levels
Mass number
Electromagnetic
force
8. Strong nuclear force
Pr
ot
1.
2.
3.
4.
5.
6.
7.
The total number of protons and
neutrons in the nucleus of an
atom
Proton
Neutron
Electron
Nucleus
Energy levels
Mass number
Electromagnetic
force
100%
0%
0%
0%
0%
0%
0%
Pr
ot
on
N
eu
tro
n
El
ec
tr
on
N
uc
En
le
us
er
gy
le
M
ve
as
ls
s
nu
El
ec
m
tr
om ber
ag
ne
ti.
..
1.
2.
3.
4.
5.
6.
7.
How many
protons?
How many
electrons?
How many
neutrons?
Draw a atomic
model for this
element?
C-12
How many
protons?
How many
electrons?
How many
neutrons?
Draw a atomic
model for this
element?
14
6
How many
protons?
How many
electrons?
How many
neutrons?
Draw a atomic
model for this
element?
7
3
How many
protons?
How many
electrons?
How many
neutrons?
Draw a atomic
model for this
element?
14
How many
protons?
How many
electrons?
How many
neutrons?
Draw a atomic
model for this
element?
Na-23
How many
protons?
How many
neutrons?
238
Be-9
atomic number?
1
2
3
4
5
6
11
96%
4%
0%
11
6
5
0%
4
0%
3
0%
2
0%
1
1.
2.
3.
4.
5.
6.
7.
Be-9
number of protons?
1
2
3
4
5
6
11
100%
0%
11
0%
6
5
0%
4
0%
3
0%
2
0%
1
1.
2.
3.
4.
5.
6.
7.
Be-9
number of electrons?
1
2
3
4
5
6
11
96%
4%
0%
11
6
5
0%
4
0%
3
0%
2
0%
1
1.
2.
3.
4.
5.
6.
7.
Be-9
number of neutrons?
1
2
3
4
5
6
11
100%
0%
11
6
0%
5
0%
4
0%
3
0%
2
0%
1
1.
2.
3.
4.
5.
6.
7.
Be-9
number of energy levels?
1
2
3
4
5
6
11
96%
4%
0%
11
0%
6
0%
5
4
3
0%
2
0%
1
1.
2.
3.
4.
5.
6.
7.
Si
valence electrons?
14
1
2
3
4
5
6
11
88%
13%
0%
11
0%
6
5
4
0%
3
0%
2
0%
1
1.
2.
3.
4.
5.
6.
7.
N
valence electrons?
7
1
2
3
4
5
6
11
96%
4%
0%
11
6
0%
5
0%
4
3
0%
2
0%
1
1.
2.
3.
4.
5.
6.
7.
1
2
3
4
5
6
11
100%
0%
11
0%
6
0%
5
0%
4
3
0%
2
0%
1
1.
2.
3.
4.
5.
6.
7.
Be-9
number of electrons in the first
energy level?
Cl
number of electrons in the first
energy level?
17
1
2
3
4
5
6
11
100%
0%
11
0%
6
0%
5
0%
4
3
0%
2
0%
1
1.
2.
3.
4.
5.
6.
7.
Complete the energy levels …
• # of Protons? 7
• # electrons? 7
2
• # e’ in
orbital?
• # e; in 2nd orbital? 5
• # of valence e’ ? 5
1st
NITROGEN
1. Who discovered the electron?
JJ Thomson
2. Electrons in the outer energy are
called?
Valence electrons
3. The columns in the periodic table
are called Groups
• NEED YOUR PERIODIC TABLE
FOR THIS ONE
Find SULFUR (atomic # 16)
• How many valence electrons
does it have? 6
• Which orbital is being filled? 3rd
1. Element or compound?? Compound
Hydrochloric acid HCl
2. What element is most closely
related to Bromine?
Fluorine / Chlorine
3. What does the group # tell us?
The # of valence electrons
• 1. Who did the gold-foil experiment?
Rutherford
• 2. Who stated that elements are made
of atoms? Dalton
• 3. What does the period # tell us?
# of the energy level being filled
• 4. Who created the term “atomos”?
Democritus
Which orbital is represented by :
A? s
B? d
C? p
B
C
A
Which 2 orbitals are we most concerned with
because of valence electrons?
s and p
Which are the metals? A
Nonmetals? B
B
C
A