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What is Chemistry?
 Chemistry is______________________________________________, especially its
properties, structure, composition, behavior, reactions, interactions and the
changes it undergoes
 Chemistry is sometimes referred to as “the central science” because it
connects ____________________with other natural sciences such as
________________________________________________________
When was the beginning of chemistry?
 Aristotle
o All matter was composed of varying combinations of the
_________________________________________________________________
o Earth,________________________________________________________,Fire
 Dalton – 1803
o All matter is made of _______________________.
o Dalton envisioned atoms as tiny spheres with hooks on them.
o With these hooks, one atom could combine with other atoms in
___________________________________________.
 J.J. Thompson - 1898
o Thomson proposed a model, sometimes called the
________________________________________________________________________________
_________, in which thousands of tiny, negatively charged corpuscles
swarm inside a sort of cloud of massless positive charge.
 Rutherford – 1911
o Rutherford suggested that the atom might resemble a tiny
____________________________________,
o with a massive, positively charged ______________________________________
circled by only a few electrons.
 Bohr – 1923
o Proposed that electrons exist in ____________________________
What does modern chemistry look like?
 The Atom
o The atom is the smallest particle of an element that retains all of the
_____________________________________________________.
o The atom has three subatomic particles: the _____________________, the
____________________, and the __________________________.
 Subatomic Particles
o A proton is a ____________________________________ found in the nucleus. It
is partly responsible for the mass of an atom.
o A neutron is a particle ___________________________________________ found in
the nucleus of an atom. It is partly responsible for the mass of an
atom.
o An electron is a __________________________________________ found outside
the nucleus. Electrons are very small and do not add much to the
mass of an atom.
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Elements
o Elements are given chemical symbols to represent them.
o The first letter (or only letter) is ______________________________.
o The second letter (if there is one) is _____________________________.
o
H is __________________________
o
O is Oxygen
o
Be is Beryllium
o
Ni is ___________________________
 Pure Substances
o A pure substance is either an ___________________________________.
o An element is a type of matter that is made up only of
__________________________________________________.
o A compound is two or more elements chemically
______________________________________________.
 Mendeleev
o In 1869, Dmitri Ivanovitch Mendeléev created the first accepted
version of the ____________________________________.
o He grouped elements according to their __________________________, and as
he did, he found that the families had similar ___________________________.
o Blank spaces were left open to add the new elements he predicted
would occur.
The Current Periodic Table
 Mendeleev wasn’t too far off.
 Now the elements are put in rows by increasing
___________________________________________
 The horizontal rows are called ______________ and are labeled from
_____________________.
 The vertical columns are called ___________________ or families and are
labeled from _____________________.
 Elements
o Science has come a long way since Aristotle’s theory of Air, Water,
Fire, and Earth.
o Scientists have identified ____________________________________________,
and created about 28 others.
 Elements
o The elements, alone or in combinations, make up our bodies, our
world, our sun, and in fact, the entire universe.
o Almost all elements are made up of 3 sub atomic particles.
______________________________________________
o The most abundant element in the Earth’s crust is oxygen.
Periodic Table
 The periodic table organizes the elements in a particular way. A great
deal of information about an element can be gathered from its
____________________________________________.
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For example, you can predict with reasonably good accuracy the
________________________________________ properties of the element. You can
also predict what other elements a particular element will react with
chemically.
Understanding the organization and plan of the periodic table will
help you obtain basic information about each of the
____________________________________.
What’s in a square?
o Different periodic tables can include various bits of
information, but usually:
o ___________________________________
o ____________________________________
o ___________________________________
Key to the Periodic Table
o Elements are organized on the table according
_____________________________________________________, usually found
near the top of the square.
o The atomic number refers to how many
_____________________________________________ atom of that element
has.
o For instance, hydrogen has 1 proton, so it’s atomic number is 1.
o The atomic number is ___________________________________. No two
elements have the same atomic number.
Symbols
o All elements have their own _____________________________.
o It can consist of a single capital letter, or a _____________________
and one or two ______________________.
o Elements have their name for a variety of reasons. Some are
named after mythology, countries, scientists or in Latin or
Greek.
Atomic Number
o This refers to how many ________________________________ an atom
of that element has.
o No two elements, have the same number of protons.
Atomic Mass
o Atomic Mass refers to the “weight” of the atom.
o It is derived at by
________________________________________________________________________
________________.
Atomic Mass Unit (AMU)
o The unit of measurement for an atom is an AMU. It stands for
atomic mass unit.
o One AMU is equal to ______________________________________.
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o There are
o
6 X 1023 or 600,000,000,000,000,000,000,000 amus in one
gram.
o (Remember that electrons are __________________________ smaller
than one amu).
Atomic Mass and Isotopes
o While most atoms have the same number of protons and
neutrons, some don’t.
o Some atoms have more or less ___________________________________.
These are called isotopes.
o An atomic mass number with a decimal is the total of the
number of protons plus the
_______________________________________________.
o We write isotopes like this:
o Uranium has 2 isotopes: Uranium – 238 & Uranium - 239
Isotopes
o Two atoms of the same element must have the same number of
protons, but they do not necessarily have to have
________________________________________________.
o
NOTE: protons never change (except in nuclear
reactions)
o
Same # of protons and different # of neutrons means
you have __________________________________________.
o Example:
o Carbon most commonly has a mass of 12
6 p + 6n = 12
o Carbon 14 has a mass of 14
6 p + 8n = 14
Isotope Examples
o List the protons, neutrons, electrons and the symbol
o Carbon – 12
o Carbon – 13
o Carbon – 14
o Note:
o The # of neutrons may vary.
o Isotopes have different mass numbers.
o Isotopes of the same element are still chemically alike because
they have the same number of protons and electrons.
Symbolizing Isotopes
o Write the ____________________________________
o Write the number of protons the element has on the bottom
_____________________________________.
o Write the mass number on the __________________________.
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Properties of Metals
o Metals are good conductors of ________________________________.
o Metals are shiny.
o Metals are ductile (can be stretched into thin wires).
o Metals are malleable (can be pounded into thin sheets).
o A chemical property of metal is its reaction with water which
results in ______________________.
Properties of Non-Metals
o Non-metals are poor conductors of ______________________________.
o Non-metals are not ductile or malleable.
o Solid non-metals are brittle and break easily.
o They are dull (not shiny).
o Many non-metals are ____________________.
Properties of Metalloids
o Metalloids (metal-like) have properties of both
__________________________________________.
o They are solids that can be shiny or dull.
o They conduct heat and electricity better than non-metals but
not as well as metals.
o They are _________________________________________.
Groups or Families
o Columns of elements are called ______________________________.
o Elements in each family have similar but not identical
properties.
o For example, lithium (Li), sodium (Na), potassium (K), and
other members of family IA are all soft, white, shiny metals.
o All elements in a family have the same
______________________________________________________.
Periods
o Each horizontal row of elements is _____________________________.
o The elements in a period are ______________________________
properties.
o In fact, the properties change greatly across even given row.
o The first element in a period is always an extremely active
solid. The last element in a period, is always an inactive gas.
o The period tells us how many ____________________ the element
has.
Group 1: Alkali Metals
o A.K.A. the ________________________________
o Very reactive
o Metallic
o Francium is the most reactive
o Six elements (Li, Na, K, Rb, Cs, and Fr)
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Group 2: Alkaline Earth Metals
o A.K.A. ________________________________________
o Six elements (Be, Mg, Ca, Sr, Ba and Ra)
o Reactive metals
o Radium is most reactive
 Group 3 and 4
o Vary from metallic and non metallic
o Very _______________________________________________.
 Group 5: Nitrogen Family
o Nitrogen and Phosphorous are non-metallic
o Bismuth is metallic
o Antimony (Sb) and Arsenic (As) exhibit properties of both
_______________________________________.
 Group 6: Oxygen Family
o ________________________ on the top and ___________________ on the
bottom.
 Group 7: Halogen Family
o Very active non-metals
o _______________________ is the most reactive
 Group 8: Noble Gas Family
o Outer shell of ___________________________________
o Very stable elements
 Transition Elements
o Fill in the d shells
o Metallic
o Number of electrons vary in _________________________________
 Rare Earth Elements
o Fill in the f shells
o Separated into series:
o Elements 58-71 are the ____________________________________
o Elements 90-103 are the ____________________________________
 Zigzag Line
o Line that separates metals from non-metals
o Elements that touch the line are called ___________________________
o Metalloids are elements that have both properties of
______________________________________________
Valence Electrons
 The number of valence electrons an atom has may also appear in a
square.
 Valence electrons are the electrons in the
______________________________________________________________.
 These are the electrons that are transferred or shared when atoms
_______________________________________.
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What does it mean to be reactive?
o We will be describing elements according to their
________________________.
o Elements that are reactive bond easily with other elements to
make _____________________________.
o Some elements are only found in nature bonded with other
elements.
o What makes an element reactive?
o An incomplete __________________________________________.
o All atoms (except hydrogen) want to have 8 electrons in their
very outermost energy level (This is called the octet rule.)
o Atoms bond until this level is complete. Atoms with less than 4
valence electrons lose them during bonding. Atoms with 5, 6,
or 7 valence electrons gain electrons during bonding.
Elements that have either gained or lost electrons are called ions.
o Positively charged: _______________________
o Any atom that loses electrons to form compounds are called
cations. Cations have a positive charge.
o Naming cations: Use the element name followed by the word
“ion”. Some Cations have more than one charged form.
o Alkali metals (group 1) have 1 valence electron and are highly
reactive because they tend to lose their valence electron E.g.
Li+, Na+, K+
o Alkaline Earth Metals (group 2) have 2 valence electrons and
therefore must give up 2 electrons E.g. Ca2+, Mg2+, Ba2+
o These are ____________________________ than group 1
Elements that have either gained or lost electrons are called ions.
o Negatively charged: _______________________________
o Atoms that gain electrons to form compounds are called
anions. Anions have a _________________________________.
o Naming Anions: Drop the last few letters of the element name
and add “ide”.
o E.g. Group 17 (Halogens) gain electrons easily and release lots
of energy in the process  highly reactive
How can we determine the charge of an ion?
o For some of the elements it is very easy. Elements in groups 1,
2, 13, 14, 15, 16, & 17 will lose or gain electrons so they have
the same # as the nearest _________________________________________
o The _______________________________________________ cannot have their
charges predicted in this way due to many of them having
isotopes. Their charges must be predicted in other ways.
Noble Gases
o Noble Gases are colorless gases that are extremely
___________________________.
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o One important property of the noble gases is their inactivity.
They are inactive because their ___________________________________
level is full.
o Because they do not readily combine with other elements to
form compounds, the ______________________________________.
o The family of noble gases includes helium, neon, argon,
krypton, xenon, and radon.
o All the noble gases are found in small amounts in the earth's
atmosphere.
Bohr’s Model of the Atom
 Electrons orbit the nucleus at a ______________________________.
 Each orbit is associated with a definite ___________________________.
 Energy levels are quantized
o Electrons travel in orbits _______________________________________
o The farther the electron is from the nucleus the more
______________________________________
 Bohr Diagrams
o These are simple diagrams that show the
_____________________________ in each orbital of an element.
o The symbol of the element is placed in the nucleus, and
electrons are then placed in each orbital.
o Let’s do a couple of examples.
 Bohr-Rutherford Diagrams
o These diagrams are a combination of a Bohr Diagram and a
Rutherford Diagram.
o The main difference between this diagram and the Bohr
diagram is the inclusion of the
___________________________________________________________________
 How To Draw Bohr-Rutherford Diagrams:
o Draw the nucleus as a solid circle.
o Put the number of protons (atomic number) in the nucleus
with the number of neutrons (atomic mass – atomic number)
under it.
o Place the number of electrons (same as protons) in orbits
around the nucleus by ______________________________________________.
Remember, 1st shell – 2 electrons, 2nd shell – 8 electrons, 3rd
shell – 8 electrons, 4th shell – 18 electrons.
Electron Dot Diagrams
 If you want to see how atoms of one element will react, it is handy to
have an easier way to represent the atoms and the
_________________________________________________
 You can do this with electron dot diagrams.
 An electron dot diagram is the symbol for the element surrounded
by as many dots as there are _______________________________________________.
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How to Write Them
o The dots are written in pairs on
__________________________________________________________________
o Start by writing one dot on the top of the element symbol, then
work your way around adding dots to the right, bottom, and
left.
o Add a fifth dot to the top to make a pair. Continue in this
manner until you reach the number of valence electrons the
element has or until there are
___________________________________________________________
 Finding Valence Electrons
o You can do this by using the ______________________ for the
element. Eg. N, K (do on board)
o You can also find it by using the period # to find # of orbitals
(shells). (use previous examples).
 Hint to make finding valence electrons easier:
o When drawing dot diagrams for an element, if the element’s
ion form has a positive charge, that # on the charge is the
number of valence electrons.
o If the ion form has a negative charge, that # on the charge is the
# of electrons required to fill the outer orbital to a total of 8
electrons.
Forming Compounds
 Sodium is an element.
 Chlorine is an element.
 When sodium and chlorine bond they make the compound
_______________________________________, commonly known as table salt.
 A _____________________________ is formed when valence electrons of atoms
interact and become stable.
 Ionic Compounds – substances composed of cations and anions forming ionic
bonds.
 Certain combinations of elements form ionic bonds (__________________________
with group 16 & 17 nonmetals).
 Eg. ____________________________
 Covalent bond – A bond formed when atoms share
________________________________________________.
 A neutral particle that is composed of atoms joined together by covalent
bonds is called a _________________________________.
 Eg. Diatomic molecules
o Molecules that contain two (“di”) atoms.
o “The Magic 7” + Hydrogen – These elements are
_____________________________________________________________, they are always
in pairs. Mark them on your periodic table.
o H, N, O, F, Cl, Br, I, At
o These start at the element #7
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o They form the shape of a 7
 Crossing Over Method
o Take down the examples!!
 Polyatomic Ions
o Consists of ____________________________________________ like ammonium
(NH4 = Nitrogen and 4 Hydrogen). See list on page 159.
o Eg. NH4+ + OHNH4OH = Ammonium hydroxide
o _________________________________ may be needed for polyatomic ions.
o Fe3+ + OHFe(OH)3 = Iron (III) hydroxide
 Things to look for
o If cations have ( ), the number inside the ( ) is ________________________.
Not how many molecules of the element.
o If anions end in -ide they are probably off the periodic table
(Monoatomic)
o If anion ends in -ate or -ite it is _____________________________________.
o The positive piece always gets written first.
o Hydrogen- it depends on where it’s at
o If it is first, it is a metal – _____________________________________
o If it is second, it’s a nonmetal - ________________________________
Writing Chemical Equations
 ______________________________: are the chemicals that are made or produced in
the reaction.
 ______________________________: are the chemicals that begin or go into the
reaction before it takes place.
 Chemical reaction: when the chemicals that go into the reaction
(___________________________) change and new chemicals (______________________)
are formed.
 When we write these “skeleton equations”, we must be sure that each
_____________________________________________.
 We will learn how to balance these equations later.
 Symbols in an equation
o “+” tells us that 2 compounds are combining. Key words that tell us
this are: _______________________________.
o ----------- acts like an equal sign to separate the
_____________________________________. Key words: to form, to produce, to
make, synthesizes, decomposes, etc.
 Balancing Equations
o _________________________________________ – a theory to explain the nature of
all matter: all matter is made up of small particle called atoms, which
can neither be created or destroyed.
o _________________________________________ – in a chemical equation, the total
mass of the products is always the same as the total mass of the
reactants.
o These 2 laws demand that the products and reactants have to have the
_______________________________________.
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o 5 sodium atoms + 5 Chlorine atoms = 10 atoms of table salt.
o Chemists use symbols instead of words to describe a chemical
equation.
o We always start with the _____________________________ for the reaction.
o After the skeleton equation you must balance the equation to satisfy
the conservation of mass law and Dalton’s theory.
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o We balance the equation by adding numbers (coefficients) to the
___________________________________________ in the reaction.
o We have to count the number of atoms on each side of the reaction
and make them all equal. We will do this for this reaction on the
board.
o WRITE THE EXAMPLE IN YOUR NOTES
Steps to balancing equations:
1. Write a skeleton equation from the word equation.
2. ____________________________ on each side of the equation.
3. Add appropriate numbers to the front of the compound or element
until the equation is balanced.
 NOTE: Always balance oxygen (O) second last and hydrogen (H) last.
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Balancing Equations Examples: (WRITE THE EXAMPLES OUT)
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