Bellwork (Get out Study
Guide..and..)
1) Tear out sheet of paper from
notebook.
2) Come up with three possible test
questions. Write the answer on the
back.
3) Trade with neighbor and see if they
can answer them (without you
telling them the answer 
Study Guide: first page
• Atomic Mass: mass of a specific isotope of an element
• Atomic Number: the number of protons in an element
• Mass Number: Protons + Neutrons
• Isotopes: forms of elements that have different number of
neutrons
• Ions: charged atoms
• Valence electrons: electrons in the outermost shell
Study Guide: First Page
Charge
Proto
n
Neutr
on
Electr
on
Positive
Neutral
Negative
Location
Mass
Nucleus
1 atomic
mass unit
Nucleus
1 atomic
mass unit
Cloud
0.00054 amu
(small!)
Study Guide: First Page
• Which particle defines the element?
• Number of protons
• What charge does the nucleus of an atom normally
have?
• Positive
• What does it mean for an atom to be neutral?
(Explain using the words proton, neutron, electron)
• No charge. Number of protons= electrons. Neutrons
are not charged.
• How are the electrons arranged in an atom?
• In shells or orbitals based on energy level.
• Knowing that every periodic table is
different, how do I tell which one thing
is the atomic number?
• It is the whole number (no
decimals).
• Knowing that every periodic table is
different, how do I tell which one thing
is the atomic mass?
• It is the decimal number. It is usually
larger than the atomic number.
• If you know an elements Atomic
number, what else do you know
about the element? (Assume the
element is neutral)
• Number of protons. If the
element is neutral, also the
number of electrons.
• How do you get the mass number
from the periodic table?
• Round the average atomic
mass. Most of the time, though,
you should add protons and
neutrons.
Study Guide: First Page
• Electrons do not travel in an orbit.
Explain this statement, using the
words orbit, orbital, electron cloud,
and energy level.
• Electrons are found approximately in
the electron cloud and travel very
quickly in orbits. They are found at
different energy levels. Electrons
closer to the nucleus have less energy
because they are strongly attracted to
the nucleus.
Isotopes and Ions
• What do the numbers after the name of an element
represent? Ex. Magnesium – 26
• Mass number. Ex) 26 is the number of protons plus
neutrons
In the example to the right, why don’t I have to include
the number of protons before Magnesium? Ex.
Magnesium – 26
The number of protons is always the same for a specific
element (it is the atomic number)
Isotopes and Ions
• Assume you have these 2 elements: 5525Mn and
• How are these elements different from each other?
•
Different mass numbers
• What do we call these elements?
•
Isotopes
• How would you name each element?
Manganese-55 and Manganese-56
56 Mn
25
Isotopes and Ions
Element/Isotope
Information
Write the
Notation
Isotope Name
the
Element/Isotope
p = 19 , e= 19, n = 39
20
19 K
Potassium-39
p=75, e=75, n =
111
186
75 Re
p = 18, e = 18, n = 40
22
18 Ar
Rhenium- 186
Argon-40
• What is a cation?
• Positively charged atom (has
lost electrons)
• Does a cation have a
positive or negative charge?
• Positive
• What is an anion?
• Negatively charged atom
(has gained electrons)
• Does an anion have a
positive or negative charge?
• Negative