BEAT Chemistry! (BE Able To): Atoms
 Explain the five parts of Dalton's Atomic Theory and know which parts are still true
1.) All matter is composed of atoms
2.) Atoms are indivisible and indestructible-FALSE
3.) All atoms of the same element are identical in mass and properties- FALSE
4.) Compounds are formed by a combination of two or more different kinds of
atoms
5.)A chemical reaction is a rearrangement of atoms
 Describe the subatomic particles, including their properties, how and when they
were discovered, and where they are located
Proton
Neutron
Electron
Charge
+ positive
- Negative
neutral
Location in
atom
Who discovered
particle
Nucleus
Nucleus
Electron cloud
Rutherford
Chadwick
Thomson
 Explain Rutherford's Gold Foil Experiment, J.J. Thomson plum pudding model,
Dalton’s model, Bohr’s model, and the Quantum Mechanical Model. Explains any
experiments run and conclusions drawn from each experiment. Refer to your
notes and homework.
Daltons
Model
All matter is
composed of
atoms
-Atoms are
indivisible and
indestructible
(WRONGAtoms are
actually
DIVISIBLE)
-All atoms of
the same
element are
identical in
mass and
propertieS
2015-2016
Thomson’s Model
Rutherford’s Model
Gold foil experiment
Plum Pudding
Model
-Discovered
electron using
an experiment
involving
cathode ray
tube
- Proved to
Dalton that the
atom is in fact
divisible.
-Most alpha particles
passed through gold
foil which proved
atom is mostly empty
space.
- A few were
deflected proving a
small dense
positively charged
nucleus
Niels Bohr
Model
The atoms has a
small, positively
charged nucleus
surrounded by
electrons that
travel in circular
orbits, similar to
the planets in
the solar
system.
Found energy
level
Quantum
Mechanics Model
describes region
of space (cloud)
where an
electron will
probably be
-Electron clouds
are called
orbitals: s, p, d, f
- Current atomic
model
BEAT Chemistry! (BE Able To): Atoms
 Fill in the table below
Element
Atomic
Number
Mass
Number
Atomic
Mass
Protons
Electrons
Neutron
Hyphen
notation
Indium
49
115
192.217
49
49
66
Ir-115
Vanadium
23
51
50.942
23
23
28
V-51
Vanadium
23
50
50.942
23
23
27
V-50
Tin, Sn2+
50
119
118.711
50
48
69
Ion
 Define isotope and explain how isotopes are similar and different.
Alike
Different
Have the same number of protons and
Have a different number of neutrons
electrons
and mass number
191
192
Os-191 has 115 neutrons
For Example: 76𝑂𝑠 and 76𝑂𝑠
Os-192 has 116 neturons
Os has 76 protons and 76 electrons
 Determine the number of protons, neutrons and electrons in isotopes written in
general format and hyphen notation.
Isotope
General
format
Ti-46
46
22𝑇𝑖
Ti-47
47
22𝑇𝑖
Number of
protons
22
Number of
electrons
22
Number of
neutrons
46-22=24
Mass Number
22
22
47-22=25
47
46
 In Tungsten-184, 184 represent the mass number? What does the mass number
tell us?
184= mass number= protons + neutrons. Find p+, neutrons, and e-.
P+=74 E=74
N=(184-74)= 110 neutrons
 Are the following atoms electrically neutral or do they carry a charge and represent
an ion?
Electrically neutral and why? OR
Charge on the ion and why
5 protons and 5
Neutral
5p+
= 0 charge neutral atom
electrons
5e-
2015-2016
7 protons and 10
electrons
Ion
7p+
10e-
= 3- charge , gained 3 e-
12 protons and 10
electrons
Ion
12p+
10e-
= 2+ charge , lost 2 e-
BEAT Chemistry! (BE Able To): Atoms
 Calculate the average atomic mass of an element. Refer to your homework
problems for examples.
Element Q has 3 naturally occurring
isotopes. What is the average atomic mass
of element Q?
Isotope
Q-39
Q-40
Q-41
(38.964 X
(39.964 X
(40.962 X
Mass (amu)
38.964
39.964
40.962
%
Abundance
93.258
.01180
Remainder
(6.7302)
.93258) +
.0001180) +
.067302)
39.099 amu
A.) What is element Q?
Potassium
B.) Does your answer make sense?
Explain.
Yes. Because my answer is 39.099 and is
closets to the most abundant isotope of Q39
2015-2016
Element X has 3 naturally occurring
isotopes. The first isotope has an atomic
mass of 28.00 amu and a percent
abundance of 14.5% The second isotope
has an atomic mass of 29.00 amu and a
percent abundance of 66.00%. The third
isotope has an atomic mass of 27.4 amu
and a percent abundance of 19.5%
What is the atomic mass of element X?
(28.000 X
(29.00 X
(27.4
X
.145) +
.66) +
.195)
28.543 amu
A.) What is element X?
Silicon
B.) Does your answer make sense?
Explain.
Yes. Because my answer is 28.543 and is
closets to the most abundant isotope of
29.00