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MATTER AND ENERGY
CHAPTER TWO
Concepts
• Matter consists of elements and compounds,
which in turn are made up of atoms, ions, or
molecules
• Whenever matter undergoes a physical or
chemical change, no atoms are created or
destroyed (the law of conservation of
matter)
What is matter?
• Three physical states:
– Solid
– Liquid
– Gas
• Two chemical forms of matter:
– Elements
– Compounds
STATES OF MATTER
Other facts about matter:
• The smallest unit of
matter is ___?
• What is an ion?
• What is a molecule
and how are they held
together?
• What are subscripts
and what do they
represent?
• The three physical
states of matter on
earth are____.
Building Blocks of Matter
• Atoms (most basic)
• Molecules
• Ions
What is an element?
• A fundamental type of matter that has a
unique set of properties and cannot be
broken down into simpler substances by
chemical means
• Periodic table: elements arranged based on
their chemical behavior
Some important elements
• Composition of the
earth’s crust
• Inorganic compounds
• All compounds that do
not contain carbon
• Crust - outermost
layer of earth - mainly
inorganic minerals and
rocks
Atomic Theory
• All elements are made of atoms
• Most widely accepted scientific theory in
chemistry
The Atom
• Major parts of the
atom are:
– Protons
– Neutrons
– Electrons
• The protons and
neutrons form the ___
• Electrons are located
in ____
• What is the atomic
number?
• What is the mass
number?
• What are isotopes?
• How do you identify
isotopes in the
symbol?
ISOTOPES
Molecule
• A second building block of matter
• Combination of two or more atoms of the
same or different elements held together by
chemical bonds
• Basic building blocks of any compound
WHAT ARE IONS?
• IF AN ATOM HAS 11 PROTONS AND 10
ELECTRONS IT IS A ______ION.
• IF IT HAS 17 PROTONS AND 18
ELECTRONS IT IS A ___ ION.
• HOW ARE THE CHARGES ON AN ION
SHOWN AFTER THE SYMBOL?
Holding atoms together
• What does a chemical
formula tell you?
• What are the
characteristics of ionic
bonds?
• What is an example of
an ionic bond?
• What are covalent
bonds?
• What is an example of
a covalent bond?
• What are hydrogen
bonds?
• What is an example of
a hydrogen bond
compound?
Covalent bonds
Other important compounds
Hydrogen bonds
What are organic compounds?
• What element do all
organic compounds
contain? What other
elements can be also
combined?
• Organic compounds
can be natural or
synthetic.
• Most organic
compounds are
covalent bonds.
P 38
• Organic Molecules
– Monomers
– Polymers
Types of organic compounds:
• Hydrocarbons made
up of ___
• Chlorinated
hydrocarbons
– An example would be:
• Chlorofluorocarbons – An example would be:
• Simple carbohydrates
• Monomers
• Polymers
• Complex
carbohydrates
• Proteins
• Nucleic acids
MORE ON PROTEINS:
• ALPHA-AMINO
ACIDS - 20
DIFFERENT
MONOMERS - # &
SEQUENCE
SPECIFIED BY
GENETIC CODE IN
DNA MOLECULES
IN CELLS
• NUCLEIC ACIDS DNA & RNA MADE BY LINKING
MONOMERS
CALLED
NUCLEOTIDES
TOGETHER
• GENES SEUQENCES OF
NUCLEOTIDES CARRIES A CODE
WHICH CONTAINS
TRAITS PASSED
FROM PARENTS TO
OFFSPRING
• GENOME - ALL OF
THE GENETIC
INFORMATION FOR
AN ORGANISM.
• What are GENE
MUTATIONS?
• What are
CHROMOSOMES?
Matter quality
• A measure of how
useful a matter
resource is - based on
availability and
concentration
• High quality matter organized,
concentrated and
usually found near
earth’s surface
• Low quality disorganized,
dilute,often deep
underground or
dispersed in the ocean
or atmosphere - have
little potential use as a
matter resource.
Matter Quality
WHAT IS ENERGY?
•
•
•
•
What is ENERGY ?
What is WORK?
What is a FORCE?
Forms of energy - light, heat, electricity,
chemical energy, mechanical energy, and
nuclear energy
Types of energy
• What is Kinetic
energy?
• What does it depend
on?
• Examples: wind,
flowing water,
electricity,
electromagnetic
radiation, heat,
temperature
• What is Potential
energy?
• What does it depend
on?
• Potential energy
changes into kinetic
energy etc.
Electromagnetic spectrum
• Transverse waves
• Different wavelengths and frequencies
• Ionizing radiation - harmful forms of
electromagnetic radiation
• Non-ionizing radiation - does not contain
enough energy to form ions
Temperature
• What is temperature?
– The average speed of the
motion of the molecules in
a given sample of matter
• What is heat?
– The total kinetic energy of
all the moving molecules
within a given substance
How is heat transferred?
• What is convection?
• What is Conduction?
• What is Radiation?
Energy quality
• An energy source’s ability to do useful
work
• High-quality - organized or concentrated can perform useful work
– Electricity, coal, gasoline, sunlight,uranium
• Low - quality - disorganized or dispersedcan perform little useful work
– Heat in water, air, etc.
Changes in Matter
• Physical
• Chemical
• Nuclear
Changes in matter
• What is a Physical
change?
• What are some
examples of physical
changes?
• All changes involve
energy - taken in or
released
• What is a Chemical
change ?
• What is an example?
• What is a
CHEMICAL
Equation?
• Reactants --> products
Law of Conservation of Matter
• All the matter on earth is here and cannot be
“thrown away” - there is no “away”
• Earth is a closed system
• Matter cannot be created nor destroyed
• Matter is not consumed
Nuclear changes
• Natural radioactivity- when nuclei of certain
isotopes spontaneously break down into one
or more different isotopes
–
–
–
–
Three types:
1. Natural radioactive decay
2. Nuclear fission
3. Nuclear fusion
Law of Conservation of matter
and energy
• Applies to nuclear changes because a
certain amount of mass (matter) is changed
into energy.
• The TOTAL amount of matter and energy
involved remains the same
What are Pollutants?
• Severity of their
effects depends on:
• Three categories:
– Degradable –
nonpersistent
– Biodegradable
– Slowly degradable -
– Chemical nature
– Concentration
– Persistence
• Presistent
– Nondegradable
•
Nuclear Changes
• Changes in the nucleus
of the atom
• Three types:
– Natural radioactive
decay
– Nuclear fission
– Nuclear fusion
Natural radioactive decay
Unstable isotopes radioisotopes spontaneously break
down and emit:
• Alpha particles positively charged
helium nuclei
• Beta particles - high
speed electrons
• Gamma rays - high
speed ionizing
electromagnetic
radiation
Half-life
• Rate of decay
• Time needed for one half of the nuclei in a
radioisotope to decay and emit their
radiation
• Eventually forms a new element
• Is not affected by temp. pressure, chemical
changes, etc.
• Rule is store for 10 half-lives for safety
Nuclear fission
• Nuclei of atoms with
large mass numbers
are split into lighter
nuclei
• Neutrons used to split
• Releases more
neutrons and energy
• Critical mass - needed
to start reaction
More on fission
• Atomic bombs uncontrolled nuclear
fission
• Damage cells
• Used in nuclear power
plants
Nuclear fusion
• Two isotopes of light
elements are combined
under great heat and
pressure to form a
heavier nucleus
• Harder to initiate
• Thermonuclear
weapons
• Ionizing Radiation – from natural or
background sources
– Can come from space, soil, food, etc.
– Has energy to knock electrons from atoms
• Can disrupt living cells, interfere with body
processes and cause cancer.
– Nonionizing radiation doesn not contain
enough energy to form ions.
First law of thermodynamics
• In all physical and chemical changes,
energy is neither created nor destroyed but
it may be converted from one form to
another
• Energy input always equals energy output
• You can’t get something for nothing cannot get more energy out of a system than
is put in!!!
Second law of thermodynamics
• When energy is changed from one form to
another, some useful energy is always
degraded to lower quality less useful energy
usually heat lost to the environment
• We ALWAYS end up with less useful
energy than we started with.
• An incandescent light bulb - 5 % light, 95%
heat
More on 2nd law
• We can NEVER recycle or reuse high
quality energy to do useful work.
• You get high quality matter and energy in
your body, you use it and you add low
quality waste matter and heat to the
environment.
What is energy efficiency?
• A measure of how much useful work is
accomplished by a particular input of
energy into a system
• Always measured as a percent (%)
• Affects life because you get and use high
quality matter and energy , use it and add
low quality heat and waste back into the
environment.