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TRANSCRIPT
© Stephanie Elkowitz
Name: ____________________________
Atoms & The Periodic Table
WHAT IS AN ATOM?
• What is an atom?
• ______________________________________________________________________________
______________________________________________________________________________
• All ______________ are made of atoms. The ______________, your ______________ and
even ______________ ______________ are made of atoms.
• Atoms are ______________ ______________. One atom is only one ______________ of a
meter wide!
DEMOCRITIS
• The idea of an atom was first developed around ______________ by Greek philosopher
______________. Democritus believed that you could not ______________ break an object
in half. At some point, you get to the ______________ bit of matter, which cannot be broken.
He called this bit of matter an ______________.
JOHN DALTON
• In ______________, English chemist John ______________ proposed and published his
theory on atoms. Dalton believed ______________ was made of extremely small
______________. Atoms of the same substance have identical ______________,
______________ and other properties. Dalton also believed atoms could not be
______________, ______________ or ______________ but could combine to form different
chemical substances.
J.J. THOMSON
• In ______________, English physicist J.J. ______________ discovered the ______________.
Thomson discovered that an electron is a tiny, ______________ charged particle. From this
finding, Thomson proposed the first ______________ of an atom.
• Thomson came up with his model of the atom in ______________. According to Thomson, an
atom was made of ______________ charged particles (______________) embedded in a
“soup” of ______________ charges.
• Why was Thomson’s atomic model called the plum pudding model?
• ______________________________________________________________________________
______________________________________________________________________________
• Draw a picture of Thomson’s plum pudding model.
ERNEST RUTHERFORD
• Ernest ______________ proposed an alternative model in ______________. According to
Rutherford, an atom is made of a central, ______________ charged region. He called this
region the ______________. Rutherford believed electrons surrounding the nucleus as a
“______________.” He also believed the nucleus of the atom was ______________ and
______________ compared to the overall size of the atom.
© Stephanie Elkowitz
• Draw a picture of Rutherford’s atomic model.
• Rutherford proved his model of the atom with a famous experiment known as the
______________ ______________ experiment.
• Who did Rutherford work with on this experiment?
1. ___________________________
2. ___________________________
• In this experiment, Rutherford shot a beam of ______________ charged particles, called
______________ particles, at a thin piece of ______________ foil. He recorded where the
alpha particles ______________ as they struck the gold foil.
• What should have happened if Thomson’s model was correct?
• ______________________________________________________________________________
______________________________________________________________________________
• What did Rutherford actually observe during this experiment?
• ______________________________________________________________________________
______________________________________________________________________________
• Rutherford believed his model explained these results:
1. Most particles ______________ through because an atom is mostly ______________
______________.
2. Some particles ______________ because they were deflected by negatively charged
______________.
3. Some particles ______________ back because they bounced off the positively
charged ______________.
NEILS BOHR
• In 1914, Neils ______________ modified Rutherford’s model of the atom. Like Rutherford,
Bohr believed an atom is made of a small, ______________ charged nucleus surrounded by
______________ charged electrons.
• How was Bohr’s atomic model different from Rutherford’s?
______________________________________________________________________________
______________________________________________________________________________
• Draw a picture of the Rutherford-Bohr atomic model.
© Stephanie Elkowitz
ATOMIC STRUCTURE
• According to this model, there are 2 major regions of an atom:
1. ___________________________________________________________________________
2. ___________________________________________________________________________
• Atoms are VERY tiny! There are so small, that we use special units of ______________ to
describe the ______________ and ______________ of atoms and particles within atoms.
• We measure the mass of atoms and the particles with an atom in ______________
______________ units (u). One atomic mass unit equals ______________ kilograms.
• We measure the size of atoms in ______________ (pm). One picometer equals one
______________ of a meter. In other words, 1 picometer equals ______________ meters. An
atom is approximately ____ pm wide.
• ______________ particles are the particles found within an atom. They are:
1. ___________________________
2. ___________________________
3. ___________________________
• Describe each subatomic particle in the table below.
Particle Location Charge Mass
Proton
Neutron
Electron
• Label the subatomic particles in the atom below.
• Because the nucleus contains ______________ and ______________ particles, the net
charge of the nucleus is ______________. A force known as the ______________ force holds
the proton(s) and neutron(s) together in the ______________.
• The space around the nucleus is ______________ charged because it contains negatively
charged ______________. ______________ stay in orbit around the nucleus due to
______________ force. This force “______________” an atom together.
• Although we cannot view the arrangement of ______________ particles within an atom, we
have an instrument that allows us to see the ______________ of atoms. A ______________
______________ microscope (STM) can view the atoms on the surface of an object.
© Stephanie Elkowitz
ELEMENTS
• All atoms have the same ______________ of subatomic particles. A change in the
______________ of subatomic particles will change the ______________ of atom.
• An ______________ is a type of atom with the same number of ______________. We also
use the term element to describe a ______________ that is made of the same type of atom.
• An element is often abbreviated with a one of two letter ______________.
• Complete the tables below to show the symbol for several common and important elements.
Element Symbol Element Symbol
Hydrogen Neon
C Helium
Oxygen F
Nitrogen Cl
Na Aluminum
Li Fe
ELECTRON SHELLS
• Electrons constantly move around the ______________ of an atom. They orbit the nucleus in
specific ______________ or ______________ that surround the nucleus. A shell is also called
an ______________ ______________. It called so because a shell is associated with a
certain amount of ______________.
• The shell closest to the nucleus has the ______________ energy. ______________ in this
shell have the least amount of energy. As you move away from the nucleus, the
______________ associated with a shell ______________. Electrons in the shell furthest
away from the nucleus have the ______________ energy.
• Each shell can only hold so many ______________:
- The first shell can hold ______________ electrons.
- The second shell can hold ______________ electrons.
- The third shell can hold ______________ electrons.
- The fourth shell can hold ______________ electrons.
• In large atoms, you can find up to ______________ shells. No shell can hold more than
______________ electrons.
ELECTRON CONFIGURATION
• How electrons are arranged in the shells of an atom is called ______________
______________. Electrons “fill” or take up ______________ in each shell.
• In general, electrons fill ______________ shells first because lower shells have
______________ energy. Once a shell is full, electrons begin to fill the next ______________
shell.
BOHR DIAGRAM
• To show electron configuration, we draw a diagram called a ______________ Diagram. To
draw a Bohr Diagram:
1. Draw a ______________ to represent the nucleus of an atom.
© Stephanie Elkowitz
2. Write the ______________ of the element, the number of ______________ and
number of ______________ inside the circle.
3. Draw ______________ around the circle to represent electron shells.
4. Draw electrons as ______________ on the rings. Remember, each “ring” can only
hold so many electrons.
• Draw a Bohr diagram of Carbon, which has 6 protons, 6 neutrons and 6 electrons.
• Draw a Bohr diagram of Sodium, which has 11 protons, 12 neutrons and 11 electrons.
VALENCE ELECTRONS
• The electrons found in the outermost orbital are called ______________ electrons. For this
reason, the outermost shell is also called the ______________ shell. The number of
______________ electrons determines many chemical ______________ of an element.
• An atom cannot have more than ______________ valance electrons. An atom with
______________ valance electrons is said to have a ______________ outer shell. For
example, ______________ has 8 valance electrons.
• Helium has a full valance shell with only ______________ electrons. Helium only has one
shell. The maximum amount of electrons held in the first shell is ______________ electrons.
Since the shell holds the maximum amount of ______________ it can hold, Helium is said to
have a ______________ valance shell.
ATOMIC NUMBER & MASS
• There are two important numbers associated with an element that help you determine the
number of protons, neutrons and electrons in a neutral atom of that element:
1. ___________________________
2. ___________________________
© Stephanie Elkowitz
ATOMIC NUMBER
• What is atomic number?
• ______________________________________________________________________________
______________________________________________________________________________
• Atoms of the same ______________ have the same number of ______________ and thus,
the same ______________ number.
ATOMIC MASS
• Atomic mass is the ______________ of an atom. Atomic mass is measured in
______________ ______________ ______________.
• Atomic mass equals the sum of ______________ and ______________ in an atom.
Remember, the mass of a proton is ______________ and the mass of a neutron is
______________.
• Why do electrons not contribute to the mass of an atom?
______________________________________________________________________________
______________________________________________________________________________
• Example: Carbon has 6 protons and 6 neutrons. What is carbon’s atomic mass?
• If you know an atom’s ______________ number and the number of ______________, you
can calculate atomic mass.
• Write the equation to calculate atomic mass:
• ______________ + ______________ = ______________
• If you know an atom’s atomic mass and atomic number, you can calculate the number of
______________ in an atom.
• Write the equation to calculate number of neutrons:
• ______________ − ______________ = ______________
• Example: Nitrogen has an atomic mass of 14. Its atomic number is 7. How many neutrons
are found in this atom?
ATOMIC VARIATIONS
• The number of ______________ is the same for all atoms of a specific ______________.
• A change in the number of ______________ will change the ______________ of atom – the
______________ to which the atom belongs.
• The number of neutrons and electrons in an atom can ______________ without changing
the ______________ to which the atom belongs.
• A change in the number of ______________ will change the ______________ of an atom.
Different forms of atoms are called ______________.
• The change in the number of ______________ will change the ______________
______________ of an atom. Atoms with electric charge are called ______________.
© Stephanie Elkowitz
ISOTOPE
• An ______________ is a variety of an element with a different number of neutrons. The
name of an isotope is the name of the element followed by a dash (_____) and the atomic
______________ of the isotope.
• Carbon has 6 protons. How would you write the name of:
1. Carbon with 6 neutrons? ______________________
2. Carbon with 7 neutrons? ______________________
3. Carbon with 8 neutrons? ______________________
AVERGE ATOMIC MASS
• What is average atomic mass?
______________________________________________________________________________
______________________________________________________________________________
• To find average atomic mass:
1. Identify the different ______________ of the element and the atomic
______________ of each isotope.
2. Multiply the atomic mass of each ______________ by its ______________
______________ (in decimal form). Percent ______________ is the percent the
element is found in the ______________ ______________.
3. Find the ______________ of these values. The sum is equal to ______________
atomic mass.
• Example: Chlorine
• Average atomic mass gives you an idea as to what the most common ______________ of an
element is. To find the most common ______________, round ______________ atomic mass
to the nearest whole number. This “trick” works for most elements.
RADIOACTIVE ISOTOPE
• Most isotopes are ______________. Stable isotopes have a “happy” ______________ of
protons and neutrons.
• Some isotopes are not ______________. An unstable isotope is called a ______________
isotope. A radioactive isotope is called so because it emits ______________.
• What is radiation?
• ______________________________________________________________________________
______________________________________________________________________________
• Why is radiation dangerous?
• ______________________________________________________________________________
______________________________________________________________________________
RADIOACTIVE DECAY
• A radioactive isotope releases ______________ in order to become ______________. This
process is called ______________ ______________.
• During ______________ decay, the atom emits ______________. ______________ can be
high-energy ______________ and/or ______________ particles.
© Stephanie Elkowitz
• As the atom undergoes radioactive decay, it becomes ______________. As a stable isotope,
the atom no longer emits ______________.
ION
• An element can gain or lose ______________ to form an ______________. An ion is an atom
with an ______________ charge.
• Neutral atoms have the same amount of ______________ and ______________. These
atoms have zero net charge. An ion does not have the ______________ amount of protons
and electrons. These atoms have a ______________ or ______________ charge.
• When an atom loses an electron, it loses a ______________ charge. Therefore, the atom has
more protons and is ______________. A positive ion is called a ______________.
• Complete the diagram to show an atom losing an electron.
• When an atom gains an electron, it gains a ______________ charge. Therefore, the atom
has more electrons and is ______________. A negative ion is called an ______________.
• Complete the diagram to show an atom losing an electron.
• To determine the electric charge of an ion, you must know the ______________ between
protons and electrons.
• If there are more ______________, the ion is ______________. A “____” is used to denote s
positive ion. If there are more ______________, the ion is ______________. A “____” is used
to denote a negative ion.
• Write the charge as a ______________ to the right of the atom. If the ion has a +1 charge,
simply write ____. If the ion has a -1 charge, simply write ____.
• Example: A sodium atom has 11 protons and 10 electrons. How do you denote the charge
on this atom?
• Example: An oxygen atom has 8 protons and 10 electrons. How do you denote the charge on
this atom?
© Stephanie Elkowitz
• An atom wants to gain or lose electrons in order to have a complete ______________ shell.
• An atom that has only one or two valance electrons tends to ______________ those
electrons and become a ______________ ion.
• What happens to lithium and why?
______________________________________________________________________________
______________________________________________________________________________
• An atom that has nearly a full valance shell tends to ______________ electrons and become
a ______________ ion.
• What happens to fluorine and why?
______________________________________________________________________________
______________________________________________________________________________
PERIODIC TABLE
• There are more than 100 different ______________. All the known elements are organized
in a table. This table is called the ______________ ______________ of ______________.
• The periodic table displays each ______________ in a box. In most periodic tables, each box
gives 4 pieces of information about the elements:
1. _________________________
2. _________________________
3. _________________________
4. ________________________
• Elements are presented in the periodic table by order of ______________ atomic
______________.
• Elements are arranged in rows and columns in the periodic table. The rows are called
______________. The columns are called ______________.
• ______________ ______________ dictates how elements are organized in the rows and
columns of the periodic table. Elements with the same number of ______________ electrons
are placed in the same column. Elements with the same number of ______________ are
placed in the same row.
• This organization explains the ______________ of the periodic table.
• There are four major types of elements in the periodic table:
1. _________________________
2. _________________________
3. _________________________
4. _________________________
• Outline and label the major types of elements in the table.
© Stephanie Elkowitz
METALS
• Most elements are ______________.
• What are characteristics of metals?
______________________________________________________________________________
______________________________________________________________________________
• What are some examples of metals?
______________________________________________________________________________
______________________________________________________________________________
NONMETALS
• ______________ make up the majority of the universe.
• What are characteristics of nonmetals?
______________________________________________________________________________
______________________________________________________________________________
• What are some examples of nonmetals?
______________________________________________________________________________
______________________________________________________________________________
• Hydrogen is a ______________ even though it is located on the periodic table where most of
the metals are found.
METALLOIDS
• ______________ have characteristics in-between metals and nonmetals.
• Metalloids are ______________ and have a “______________ appearance.” Although they
look like metals, most metalloids are ______________, not ______________ and fair
______________.
• What are the 6 commonly recognized metalloids?
1. _________________________
2. _________________________
© Stephanie Elkowitz
3. _________________________
4. _________________________
5. _________________________
6. _________________________
• ______________ and/or ______________ are sometimes included.
NOBEL GASES
• ______________ and ______________ are sometimes included as metalloids.
• Nobel gases are ______________, ______________ elements. As their name suggests,
Nobel gases are ______________ at room temperature.
• Nobel gases are ______________ conductors.
• What are the 6 Nobel gases?
1. _________________________
2. _________________________
3. _________________________
4. _________________________
5. _________________________
6. _________________________
PERIODIC TABLE GROUPS
• Recall: Elements in the same group have the same number of ______________ electrons.
• The number of valance electrons is easy to determine for groups 1, 2 and 13 through 18.
Elements in group 1 have ____ valance electron, elements in group 2 have ____ valance
electrons and so on.
• There are ______________ to this pattern in the center block of elements and to the rows of
elements below the table. These elements are called ______________ metals.
• Transitional metals have ______________ electron configuration. Electrons are added to the
______________ to last orbital instead of the ______________ shell.
• Some groups have specific names because they share similar properties:
1. _________________________
2. _________________________
3. _________________________
4. _________________________
5. _________________________
• Elements in these groups share similar ______________ because they have the same
number of ______________ electrons.
• Outline and label the periodic table groups in the periodic table below.
© Stephanie Elkowitz
• Describe each of the groups in the table below.
Group Characteristics
Alkali Metals
Alkaline Earth
Metals
Transitional
Metals
Halogens
Nobel Gases
F BLOCK ELEMENTS
© Stephanie Elkowitz
• Below the period table are two rows of elements. These rows make up the ______________
of the periodic table. Elements in the F block are ______________ of the periodic table, but
it’s easier to ______________ them on the bottom of the table.
• Each row is considered a ______________ of elements. The first row is called the
______________ series. The second row is called the ______________ series.
LATHANIDE SERIES
• The lanthanide series includes chemical elements with atomic numbers ____ through ____.
All of these elements are shiny, ______________ ______________. These elements are
______________.
• What are some uses for Lanthanide elements?
______________________________________________________________________________
______________________________________________________________________________
ACTINIDE SERIES
• The actinide series include chemical elements with atomic numbers ____ through ____. All
of these elements are ______________.
• Some of the actinide elements are ______________ - they are not found nature. Elements
with atomic numbers ______ through ______ are synthetic elements.
• What are some uses for Actinide elements?
______________________________________________________________________________
______________________________________________________________________________
SYNTHETIC ELEMENTS
• There are other ______________ elements in the periodic table. In total, there are ____
synthetic elements. These elements have atomic numbers ____ through ____. Synthetic
elements do not occur ______________ on Earth. All synthetic elements were made in a
______________.
• All synthetic elements are ______________ and ______________. They decay
______________, some in only a few hundred ______________.
• Some elements, such as ______________ and ______________, are synthetically made.
However, they are not purely synthetic. They exist ______________ in very minute quantities
on Earth.
PERIODIC TABLE TRENDS
• There are patterns to the properties of elements in the periodic table. These patterns are
called ______________.
ATOMIC RADIUS
• What is atomic radius?
______________________________________________________________________________
______________________________________________________________________________
• How does atomic radius change as you move down a column?
______________________________________________________________________________
______________________________________________________________________________
• How does atomic radius change as you move across a row?
______________________________________________________________________________
______________________________________________________________________________
ELECTRONEGATIVITY
© Stephanie Elkowitz
• What is electronegativity?
______________________________________________________________________________
______________________________________________________________________________
• How does electronegativity change as you move across a row?
______________________________________________________________________________
______________________________________________________________________________
• How does electronegativity change as you move up a column?
• ______________________________________________________________________________
______________________________________________________________________________
IONIZATION ENERGY
• What is ionization energy?
______________________________________________________________________________
______________________________________________________________________________
• How does ionization energy change as you move across a row?
______________________________________________________________________________
______________________________________________________________________________
• How does ionization energy change as you move up a column?
• ______________________________________________________________________________
______________________________________________________________________________
METALLIC CHARACTER
• Elements, except ______________, on the left side of the periodic table are
______________. These elements have ______________ character.
• ______________ character refers to characteristics of metals.
• What are 4 characteristics of metals?
1. _________________________
2. _________________________
3. _________________________
4. _________________________
• Metalloids have some ______________ character. Nonmetals do not have ______________
character, which is why they are called nonmetals.
• How does metallic character change as you move across the periodic table?
• ______________________________________________________________________________
______________________________________________________________________________
• Summarize the periodic table trends on the table below
© Stephanie Elkowitz
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Reflection Questions
1. Summarize how the model of an atom changed over the years.
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
2. What are the similarities and differences between a proton, neutron and electron?
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
3. What happens when the amount of protons, neutrons or electrons change in an atom?
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
4. Summarize some of the important trends of the periodic table of elements.
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________