CHEMISTRY UNIT
NOTES
Chemistry Unit Notes 1
Objective 4.01: Understand that naturally occurring and
synthetic substances are chemicals
Key Terms 4.01
Chemical
Synthetic chemical
Matter
Element
Synthetic element
Mixture
Compound
Science book page numbers
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Ch 13 pgs 536-544
Notes 4.01
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Chemical—substance that used in a chemical process or that is formed by a
chemical process or it may also be any substance that is always made of the same
thing
o Ex. Water is always H2O
Chemicals can be natural or synthetic
o Natural—CO2, H2O, gold, and sugar
o Synthetic—chemicals made in the laboratory
 Ex. Plastic, steel, bronze
Matter is anything that has mass and volume
Mass is the amount of matter in a substance
Volume is the amount of space the substance occupies
The main three states of matter—solid, liquid, and gas
o Solid has a definite shape and volume—table, chair
o Liquid has a definite volume but not shape—water, oil
o Gas doesn’t have a definite volume or shape—air
Element-simplest form of matter, it can not be broken down into simpler
substances by ordinary chemical means
o Changing an element to another element requires a lot of energy such as a
nuclear explosion
o There are about 109 elements discovered
all of the known elements are combined into natural elements and synthetic
elements—93 are natural elements, synthetic elements—16 that scientists created
Mixture—when two or more substances combine but do not join together
chemically—the different parts keep their individual identities (properties)
o Ex. Cereal(mix of bran, fruit, milk, etc) and air (mix of gases)
Compound—when two or more elements combine chemically, individual
substances join and do not keep their original properties
Chemistry Unit Notes 2
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o Ex table salt (NaCl—sodium chloride), sodium by itself is a metal that
explodes in water and chlorine is a poisonous gas—together you can eat it
Mixtures and compounds can be natural or synthetic
o Minerals are examples of natural mixtures
o Stainless steel is an example of synthetic mixture
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Discussion Question 1
Briefly explain the difference between a mixture and a compound and give two examples
of each.
Chemistry Unit Notes 3
Objective 4.02: Evaluate evidence that elements combine in a
multiple of ways to produce compounds that account for all
living and nonliving substances
Key Terms 4.02
Compound
Molecule
Chemical formula
Atom
Proton
Neutron
Electron
Nucleus
Valence electrons
Ionic bond
Ion
Covalent bond
Science Book Reading
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Review Ch 13 Sec 1
Read Ch 15 Sec 1 pgs 604-609
Notes 4.02
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Compound—two or more substances chemically combine forming a new
substance
o Have a definite composition---NaCl is always table salt
o Can be broken down into simpler substances by chemical means meaning
NaCl can be broken into Na and Cl
o Can be identified by their physical properties meaning how you observe it
and measure it
Molecule—smallest unit of a compound that has all the properties of the
compound
o Ex smallest molecule of water would be H2O
Chemical formula—the makeup of a compound, uses chemical symbols and
subscripts to identify the number of atoms of each element in a molecule of a
compound
o Ex. H and O are chemical symbols of hydrogen and oxygen, 2 is the
subscript for the number of hydrogen atoms needed to bond with oxygen
to make water…this is the formula for water H2O
o When there is not a subscript for a symbol that means there is only 1 atom
present, you need one sodium and one chlorine to make salt the chemical
formula is NaCl
Atom—smallest unit of an element that has the properties of the element, also
called the building block of an matter
Chemistry Unit Notes 4
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Three types of atom particles: protons, neutrons, and electrons
o Proton—a particle with a positive charge (+)
o Neutron—a particle without a charge (neutral) ( )
o Electron—a particle with a negative charge (-)
 Protons and neutrons are found in the center of the atom called
the nucleus
 Electrons orbit the nucleus in a region called the electron cloud
 Electrons have different amounts of energy
 The closest electrons have less energy than electrons
farther from the nucleus
 Electrons on the same energy level have similar
amounts of energy
Each energy level can hold a certain number of electrons
Energy Level
Max Number of Electrons
1
2
2
8
3
18
4
32
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Valence electrons are found in the outer shell of the atom
o To determine how atoms combine to make compounds is
dependent upon the number and arrangement of valence electrons
Chemical bonds—forces that hold atoms together
o Ionic bond-when a bond is formed by losing or gaining electrons
o Ion—atom that has gained or lost one or more electrons
 Losses electrons—atom becomes positive
 Gains electrons—atom becomes negative
 Form because opposite charges attract
Chemistry Unit Notes 5
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To bond atoms need to have a total of eight electrons in their outer energy level
o Atoms with 1, 2, or 3 valence electrons normally give their electrons to
atoms of elements that have 7, 6, or 5 valence electrons
Covalent bonds—atoms share valence electrons
o Form between elements whose atoms have 4, 5, 6, or 7 valence electrons
Chemistry Unit Notes 6
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The same elements and be combined differently to form different elements
o Ex. H2O=water, H2O2=hydrogen peroxide; CO=carbon monoxide, CO2=
carbon dioxide
Atomic Theory
o All matter is composed of atoms (building block)
o Atoms of a given element are identical—same number of protons and
electrons
o Atoms of different elements combine in simple whole-number ratios to
form chemical compounds—determined by valence electrons
o Compounds can make up living or nonliving substances
 Living—proteins, carbohydrates, fats
 Nonliving—plastics, rubber, medicines
Discussion Question 2
Is it possible to change a mixture into a compound?
Objective 4.03: Explain how the Periodic Table is a model for:
 Classifying elements
 Identifying the properties of elements
Key Terms 4.03
Atomic mass
Periodic table
Atomic number
Period
Group
Reactivity
Metalloid
Inert
Science Book Reading
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Review Ch 15 Sec 1
Read Ch 15 Sec 2 pgs 610-617
Notes 4.03
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Atomic mass—equal to the number of protons and neutrons in the nucleus
Mendeleev’s periodic table arranges elements according to the atomic mass
Elements with similar properties are found in the same column
Periodic table—chart that organizes information about all of the known elements
according to their properties
Chemistry Unit Notes 7
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Today elements are in order of the atomic number
Atomic number—number of protons in the nucleus of an atom
Period is the horizontal row in the periodic table
o Numbered 1-7, arranged in order of increasing atomic number
Chemical family or group is the Vertical column on the periodic table
o All have similar properties, numbered 1-18 and from 1A to 8A, all have
same number of valence electrons
o Groups 1-2(IA-IIA) and 13-18(IIIA-VIIIA) are the main groups
o Groups 3-12 are called transition elements
o Elements on the left side of the periodic table are metals, except hydrogen
o Elements on the right side of the periodic table are nonmetals
Properties of Metal
Solid at room temperature, except mercury,
which is a liquid
Malleable(shaped) and ductile (drawn into
wire)
Have luster (shiny)
Have high thermal and electrical
conductivity
Tend to lose electrons in chemical reactions
Properties of Nonmetals
Most are gases, except bromine, which is a
liquid
Brittle in solid phase
Normally dull
Are poor conductors of heat and electricity
Tend to gain electrons in chemical
Chemistry Unit Notes 8
reactions
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Reactivity describes how likely an element is to form bonds with other elements
Hydrogen is found above Group 1 but doesn’t belong to any group. It was placed
here because it only has one valence electron. It’s properties are different from the
other groups.
Group 1 (Alkali Metals) on periodic table
o Most chemically active
o One electron in the outer shell
o Easily combine with nonmetals
o Reactivity of the metal increases with increasing atomic number
Group 2 (Alkaline Earth Metal) on the periodic table
o Highly reactive but less reactive than group 1
o Reactivity of the metal increases with increasing atomic number
Group 3 –12 (transition metals) on the periodic table
o Generally hard solids with high melting points
o Often form colored ions
Metalloids
o Found along the zigzag between the metals and nonmetals on the periodic
table
o Have properties of both metals and nonmetals
Group 17 (Halogens) on the periodic table
o Most reactive of the nonmetals
o Reactivity in nonmetals increases as atomic number decreases
o Fluorine (F) is the most reactive
o Halogens react with alkali metals to form salts
o Elements in this family are all states of matter
 Fluorine(Fl) and Chlorine—gases
 Bromine (Br)—liquid
 Iodine (I) and Astatine (At) are solids at room temperature
Group 18 (Noble Gases) on periodic table
o Least reactive of all elements
o Inert—unable to react chemically
Discussion Question 3
When looking at different versions of the periodic table, why is hydrogen normally not
attached to the periodic table?
Chemistry Unit Notes 9
Objective 4.04: Describe the suitability of materials for use in
technological design:
 Electrical conductivity
 Density
 Magnetism
 Solubility
 Malleability
Key Terms 4.04
Property
Physical property
Chemical property
Metal
Nonmetal
Metalloid
Malleable
Ductile
Magnetism
Conductor
Insulator
Semiconductor
Density
Solubility
Science Book Readings
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Review Ch 15 Sec 2
Read Ch 13 pgs 538-539
Read Ch 13 Sec 2 pgs 546-550
Read Ch 15 Sec 3 pgs 618-624
Read Ch 15 Sec 4 pgs 625-635
Notes 4.04
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Property—any factor that can be used identify and describe matter
o Helps for deciding the uses of various materials for technology
Physical property—observable and measureable characteristic without changing
the identity of the substance
o Ex Mass, volume, color, hardness, and phase
o Every substance has its own unique properties
Chemical property—how the matter will change under certain conditions, this
characteristic is unique to substances
o Ability to burn, rust, react to light, or react with acids are chemical
properties of matter
Zigzag line divides the table into metalloids, metals, and nonmetals
Chemistry Unit Notes 10
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Malleable—able to be hammered and shaped and rolled into thin sheets like foil
Ductile—able to be stretched or drawn into wires without breaking
Magnetism—attraction(moving towards) or repulsion (moving away) between
like or unlike poles—iron, cobalt, and nickel are strong magnets
Conductor—a material or substance electricity or heat easily flows through
Insulators—a material that electricity or heat doesn’t easily flow through—rubber,
wood, plastic, glass
Semiconductor—a material that has conductive properties that are variable—these
can be useful for carrying electricity under certain conditions
Density—density=mass/volume certain substances have a specific density
Solubility—measure of how much of a substance can dissolve in a certain amount
of another substance
o Carbon dioxide will dissolve more in water than oxygen, that’s why it is
used in sodas
Discussion Question 4
Insulation is used in the walls of homes to regulate the flow of heat into and out of the
house. Why would aluminum be a poor choice for insulation?
Objective 4.05: Identify substances based on characteristic
physical properties:
 Density
 Boiling/Melting points
 Solubility
 Chemical reactivity
 Specific heat
Key Terms 4.05
Physical property
Density
Melting point
Boiling point
Specific heat
Solubility
Solution
Reactivity
Chemistry Unit Notes 11
Science Book Reading
Review pgs 538-539, 549, 550
Read Ch 16 Sec 2 pgs 698-703
Read Ch 14 Sec 1 & 2 pgs 572-583
Notes 4.05
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Temperature is a physical property that is used to determine a substance because
the temperature that a substance melts or boils is specific for the that substance
Melting point—the temperature at which a solid changes into a liquid—water 0C
Boiling point—the temperature at which a liquid changes into a gas—water
100C
Specific heat—the amount of heat needed to raise 1 gram (1 g) of a substance by
1 degree Celsius
o The unit of specific heat is joules per gram per degree Celsius (J/g  C)
o Used to compare how different substances absorb heat
Substance
Specific Heat (J/g  C)
Water (liquid)
4.18
Ethanol
2.44
Water (solid)
2.06
Aluminum
0.897
Lead
0.129
Of the above substances lead heats the fastest it has the lowest specific heat
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Solubility, chemical properties, and reactivity are also identifiers of substances
Discussion Question 5
Is it possible for two different substances to have the same physical property? Explain.
Objective 4.06: Describe and measure quantities related to
chemical/physical changes within a system:
 Temperature
 Volume
 Mass
 Precipitate
 Gas production
Chemistry Unit Notes 12
Key Terms 4.06
Physical change
Chemical change
Chemical reaction
Precipitate
Reactant
Product
Science Book Readings
Review pgs 538-539
Read pgs 552-554, 556, 650-655
Notes 4.06
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Physical change-changing the physical properties of a substance without
changing the substance—melting ice it is still water, tearing a sheet of paper it is
still paper, and sharpening pencil it is still a pencil
Chemical change—changing a substance into a new substance this will make it
have different properties—involve chemical reactions Sodium is a metal and
chlorine is a gas when they react (chemically change) the new substance created
is table salt
Chemical reaction—the process by which new substances are formed, most
aren’t reversible
Sign of Chemical Reaction
Formation of precipitate
Gas formation
Color change
Energy change
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Explanation
A solid forms in a solution
If you see bubbles or visible gas
Substances change color
A rise (exothermic) or fall(endothermic) in
temperature, light is given off
Chemical bonds are either broken or formed—this requires energy—during a
chemical reaction
Energy is released whenever new bonds form to join substances together
Most chemical reactions release energy as heat, temperature rises
o Ex. Propane burns in the presence of oxygen
Chemical Reaction
propane + oxygen  carbon dioxide + water + energy (heat and light)
Reactants
Products
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Reactant—substance that takes part in a chemical reaction
Product—substance formed during a chemical reaction
Discussion Question 6
If a solid is added to water and water temperature rises from 20ºC to 26ºC, what type of
change does this indicate?
Chemistry Unit Notes 13
Objective 4.07: Identify evidence supporting the law of
conservation of matter:
 During an ordinary chemical reaction matter cannot be
created or destroyed
 In a chemical reaction, the total mass of the reactants
equals the total mass of the products
Key Terms 4.07
Law of Conservation of Matter
Law of Conservation of Mass
Molecule
Science Book Reading
Read Pgs 555, 660-667, 670-675
Notes 4.07
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Law of conservation of matter states that during a chemical reaction, matter
cannot be created or destroyed
Law of conservation of mass states that mass of the products must equal the mass
of the reactants
Discussion Question 7
Compare shuffling a deck of cards to a chemical reaction?
Objective 4.08: Identify that some chemical may contribute to
human health conditions including:
 Cancer
 Autoimmune disease
 Birth defects
 Heart disease
 Diabetes
 Learning and behavioral disorders
 Kidney disease
 Asthma
Chemistry Unit Notes 14
Key Terms 4.08
Cancer
Carcinogen
Fetal alcohol syndrome (FAS)
Kidneys
Ureter
Bronchi
Science Book Readings
Read pgs 646-647, 686-687
Notes 4.08
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Cancer—a group of diseases caused by abnormal (uncontrolled) cell growth and
reproduction
o Tumor—large mass of cells joined together
Carcinogen—chemical that causes cancer
o Ex. of chemicals that can cause cancer are asbestos and radon
Some chemicals cause birth defects
o Ex. smoking during pregnancy can increase the chance cleft lip, cleft
palate, and heart defects
o Drinking during pregnancy may cause fetal alcohol syndrome (FAS)—
causing brain damage, learning disabilities or behavioral problems, slow
growth, irregular facial features, visual and hearing problems, and some
types of heart, liver, and kidney disorders
Heart disease can be caused by nicotine found in tobacco which causes arteries to
narrow
o cholesterol is a chemical that can cause heart disease
A build up of ammonia, uric acid, and calcium can cause kidney stones
Some chemicals (cleaning products aerosols) being inhaled can trigger asthma
where the bronchi swell making it difficult to breathe
Discussion Question 8
You’ve learned about chemicals that have a negative effect on humans. What are some
chemicals that positively effect humans?
Chemistry Unit Notes 15
Objective 4.09: Describe factors that determine the effects a
chemical has on a living organism including:
 Exposure
 Potency
 Dose and the resultant concentration of chemical in the
organism
 Individual susceptibility
 Possible means to eliminate or reduce effects
Key Terms 4.09
Dose
Potency
Toxicity test
Exposure time
Concentration
Science Book Readings
Review previous readings
Notes 4.09
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Chemicals that are developed for a specific purpose can have unintended effects
on the environment, most effects aren’t noticed until a serious problem has
occurred
o Ex. DDT was made in 1873, 1939 DDT began being used as a pesticide,
1962 people discovered the negative effects of DDT on bird populations
The dose, potency, exposure time, individual susceptibility, and concentration
determines the effect a chemical will have on an organism
Dose—a chemical substance is the amount that is given to one individual,
sometimes it hard to tell what dose is appropriate
Potency—how powerful a chemical is, any drug that is said to produce visible or
measurable effect at a low dose is said to have a high potency
o Toxicity test—the test given to see how potent a drug is
 Exposure time—how long an individual is exposed to a
chemical—this is not always easy to determine do to the fact that
the stability of chemicals varies, meaning some chemicals
breakdown faster than others
Individual susceptibility—an individuals response to a chemical, which varies
depending on the individual—the factors that determine this are genetic and
physical make-up
Concentration—a chemical’s concentration refers to the amount of a substance in
a given volume—it can be calculated by knowing the mass and volume of a
Chemistry Unit Notes 16
substance—however, in the environment it is difficult to calculate because many
factors affect how far a chemical will spread
Discussion Question 9
Explain why the osprey population has recovered in the past 10 years.
Objective 4.10: Describe risks and benefits of chemicals
including:
 Medicines
 Food preservations
 Crop yield
 Sanitation
Key Terms 4.10
Risk benefit analysis
Food preservatives
Oxidation
Allergy
Food intolerance
Antibiotics
Fertilizers
Pesticides
Science Book Readings
Read pgs 762-763
Notes 4.10
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Benefits-how in the chemical meets the needs of society
Risks-the negative affects the chemical may have on the environment or for
people
Risk-benefit analysis-is the process of weighing the potential harm against the
good that will come out of using the chemical
Sanitation-all the methods of removal, treatment, and disposal of wastes
Wastewater treatment-the process of making water safe to be used for people and
other organisms
o Activated charcoal can be used to remove contaminants from water
o Chlorine used in low amounts can be used to remove contaminants from
water…low doses it cleans iron, manganese, and hydrogen sulfide from
water, drawbacks is the smell and taste of the water when it is used
Chemistry Unit Notes 17
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Food preservatives-chemicals used to prevent food spoilage caused by
microorganisms
o Some inhibit the growth of microorganisms
o Some slow oxidation or the substance reacting with oxygen
 Ex. Preventing fruit to turn brown
o Some preservatives used today include MSG, BHT, sodium benzoate,
potassium sorbate, etc
o Risks of preservatives include allergies or food intolerances
 Allergies-immune system response to proteins in the food
 Food intolerance-not able to digest a food or additive
Allergy Symptoms
Sneezing, headache, rash, coughing,
vomiting, drop in blood pressure, difficulty
breathing, swelling
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Food Intolerance Symptoms
Rash, congestion, tiredness, weight gain or
weight loss, digestive problems, headache
Medicines can be natural or synthetic they have been used for years to various
treat medical problems.
o Antibiotics is one chemical that is used to treat bacterial infections the
drawback of using antibiotics all of the time is that bacteria are able to
mutate and build up a resistance and withstand many of the older
antibiotics
Chemicals are also used to increase crop yield. Two that are used are fertilizers
and pesticides
o Fertilizers are chemicals used to promote plant growth by giving them
nitrogen, potash, other nutrients
 Risk of using fertilizers is when it rains the run-off goes into water
sources and causes an excess of algae growth
o Pesticides are chemicals used to kill organisms that hinder the growth of
plants or are pests
 Some pesticides include chemicals such as arsenic, lead, mercury,
nicotine sulfate
 The risks of using pesticides is that some organisms that aren’t
pests can be harmed
Discussion Question 10
Use examples to show that there are both risks and benefits for using chemicals.