Unit 3: Atoms and Elements – Review Notes
name:_______________________
period: ______________
Main Idea
1. What is an atom?
2. What is an element?
3. Draw and identify the basic parts of a
periodic table.
4. Where are protons, neutrons and electrons
located in an atom?
5. What is an atom mostly made up of?
Supporting Details/Answer
The smallest particle into which an element can
be divided and still be the same substance.
Pure substance that can’t be separated into
simpler substances by physical or chemical
changes.
7
N
Nitrogen
14 amu
Atomic #
Symbol
Name
Atomic Mass
Protons = nucleus
Neutrons =nucleus
Electrons = electron cloud
empty space
6. What are the charges on a proton, neutron
and electron?
Protons = positive
Neutrons =no charge; neutral
Electrons = negative
7. Where is most of the mass of an atom
located?
Nucleus because protons and neutrons are in the
nucleus and they both have mass
Electrons are in the electron cloud and have
almost no mass
amu= atomic mass unit
8. What units are used to measure the mass
of an atom?
9. Describe how to determine the number of
protons in a specific atom using the
periodic table.
The atomic number = number of protons
10. Describe how to determine the number of
electrons in a specific atom using the
periodic table.
Electrons = protons in neutral atoms
11. Describe how to determine the number of
neutrons in a specific atom using the
periodic table.
Neutrons = atomic mass - protons
12. What are some of the patterns on the
periodic table?
Down a group: atomic radius increases, number
of energy level increases, reactivity is same,
number of valence electrons is same
Across a period: number of valence electrons
increases, number of energy levels is same
Unit 3: Atoms and Elements – Review Notes
name:_______________________
period: ______________
13. What determines the type of element?
14. What is all matter made of?
Group # = number of valence electrons
Period # = number of energy levels
Metals are on the left
Nonmetals are on the right
Metalloids are along the zig zag line that
separates metals and nonmetals
The atomic number = number of protons.
The number of protons an atom has = the type of
element. No two different elements have the
same number of protons.
Atoms.
15. What are the periods and groups on the
periodic table?
Properties of matter are ways of describing matter.
16. Define chemical property of matter:
A chemical property of matter can only be observed
by reacting matter with other matter to create a new
type of matter. Chemical properties describe the
ability of a type of matter to react with other matter.
A physical property can be observed without changing
the matter into a new substance.
17. Define physical property of matter:
18. Practice drawing Bohr models. Tell how
many electrons the first three energy levels
can hold.
1. Identify
6
C
Carbon
1st energy level holds 2 electrons
2nd energy level holds 8 electrons
3rd energy level holds up to 18 but is considered
full with 8 electrons
Atomic number
Element symbol
Element name
12.0
Atomic mass
Unit 3: Atoms and Elements – Review Notes
name:_______________________
period: ______________
Word
Atomic Number
Definition
The number of protons in an atom. In a neutral atom it is
also the number of electrons.
Chemical Symbol
The symbol that represents that element
Element Name
The name of the element
Mass Number
The mass of an atom of that element. It is the total
number of protons and neutrons.
Unit 3: Atoms and Elements – Review Notes
3
name:_______________________
period: ______________
10
3
10
lithium
4
neon
10
6.941
3
20.18
10