Science, Systems, Matter, and Energy

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Chapter 2

• Science, Systems, Matter, and Energy

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TYPES AND STRUCTURE OF MATTER

• Elements and Compounds
• Matter exists in chemical forms as elements and
  compounds.
• Elements (represented on the periodic table) are
  the building blocks of matter.
• Compounds two or more different elements held
  together in fixed proportions by chemical bonds.

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Basic Chemistry

• Matter, Mass, and Weight
• Matter Anything that occupies space and has mass
• Mass The amount of matter in an object
• Weight The gravitational force acting on an
  object of a given mass
• Elements and Atoms
• Elements The simplest type of matter with unique
  chemical properties
• Atoms Smallest particle of an element that has
  chemical characteristics of that element

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Atoms
Figure 2-4
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Atomic Structure

• Atoms composed of subatomic particles
• Neutrons no electrical charge
• Protons positive charge
• Electrons negative charge
• Nucleus
• Formed by protons and neutrons
• Most of volume of atom occupied by electrons

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Atomic Number and Mass Number

• Atomic Number Equal to number of protons in each
  atom which equals the number of electrons
• Mass Number Number of protons plus number of
  neutrons

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Isotopes and Atomic Mass

• Isotopes Two or more forms of same element with
  same number of protons and electrons but
  different neutron number
• 3 types of hydrogen
• Denoted by using symbol of element preceded by
  mass number as 1H, 2H, 3H
• Atomic Mass Average mass of naturally occurring
  isotopes

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Molecules and Compounds

• Molecules Two or more atoms form a covalent
  bond
• Example Water
• Compounds A substance composed of two or more
  different types if atoms chemically combined
• Example Hydrogen Molecule
• Molecular Mass Determined by adding up atomic
  masses of its atoms or ions
• Example NaCl (22.99 35.45)

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Covalent Bonding

• Atoms share one or more pairs of electrons
• Single covalent Electron pair between 2 atoms
• Double covalent Two atoms share 4 electrons
• Nonpolar covalent Electrons shared equally
• Polar covalent Electrons not shared equally

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Electrons and Chemical Bonding

• Ion When an atom loses or gains electrons and
  become charged
• Cation Positively charged ion
• Anion Negatively charged ion
• Ionic Bonding
• Cations and anions are attracted to each other

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Ions

• An ion is an atom or group of atoms with one or
  more net positive or negative electrical charges.
• The number of positive or negative charges on an
  ion is shown as a superscript after the symbol
  for an atom or group of atoms
• Hydrogen ions (H), Hydroxide ions (OH-)
• Sodium ions (Na), Chloride ions (Cl-)

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Compounds and Chemical Formulas

• Chemical formulas are shorthand ways to show the
  atoms and ions in a chemical compound.
• Combining Hydrogen ions (H) and Hydroxide ions
  (OH-) makes the compound H2O (dihydrogen oxide,
  a.k.a. water).
• Combining Sodium ions (Na) and Chloride ions
  (Cl-) makes the compound NaCl (sodium chloride
  a.k.a. salt).

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Synthesis and Decomposition Reactions

• Synthesis Reactions
• Two or more reactants chemically combine to form
  a larger product
• Decomposition Reactions
• Reverse of synthesis reactions

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Acids and Bases Salts and Buffers

• Acid A proton donor or any substance that
  releases hydrogen ions
• Bases A proton acceptor or any substance that
  binds to or accepts hydrogen ions
• Buffers Able to maintain the pH

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The pH Scale

• Refers to the Hydrogen ion concentration in a
  solution
• Neutral pH of 7 or equal hydrogen and hydroxide
  ions
• Acidic a greater concentration of hydrogen ions
• Alkaline or basic a greater concentration of
  hydroxide ions

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• The pH (potential of Hydrogen) is the
  concentration of hydrogen ions in one liter of
  solution.

Figure 2-5
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Chemistry

• Inorganic Chemistry Generally substances that
  do not contain carbon
• Water
• Oxygen
• Organic Chemistry Study of carbon-containing
  substances

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Organic Compounds Carbon Rules

• Organic compounds contain carbon atoms combined
  with one another and with various other atoms
  such as H, N, or Cl-.
• Contain at least two carbon atoms combined with
  each other and with atoms.
• Methane (CH4) is the only exception.
• All other compounds are inorganic.

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Organic Chemistry

• Carbohydrates
• Composed of carbon, hydrogen, oxygen
• Lipids
• Composed mostly of carbon, hydrogen, oxygen
• Proteins
• Composed of carbon, hydrogen, oxygen,nitrogen
• Nucleic Acids DNA and RNA
• Composed of carbon, hydrogen, oxygen, nitrogen,
  phosphorus
• Adenosine Triphosphate (ATP)
• Composed of adenosine and three phosphate groups

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Carbohydrates

• Monosaccharides or building blocks
• Simple sugars glucose, fructose, galactose
• Disaccharides
• Two simple sugars bound together by dehydration
  sucrose, lactose, maltose
• Polysaccharides
• Long chains of many monosaccharides glycogen in
  animals starch and cellulose in plants

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Lipids

• Lipids Can be dissolved in nonpolar organic
  solvents as alcohol or acetone but relatively
  insoluble in water
• Fats, Oils and Waxes.
• Triglycerides composed of glycerol and fatty
  acids
• Phospholipids Important structural component of
  cell membranes
• Steroids Cholesterol, bile salts, estrogen,
  testosterone
• Fat-soluble Vitamins

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Proteins

• Amino acids The building blocks of protein
• Peptide bonds Covalent bonds formed between
  amino acids during protein synthesis
• Structure
• Primary, secondary, tertiary, quartenary
• Enzymes Protein catalysts
• Lock-and-key model
• Active site
• Coenzymes

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Protein Structure and Enzyme Action
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Nucleic Acids DNA and RNA

• DNA Deoxyribonucleic acid
• Genetic material of cells copied from one
  generation to next
• Composed of 2 strands of nucleotides
• Each nucleotide contains one of the organic bases
  of adenine or guanine which are purines and
  thymine or cystosine which are pyrimidines
• RNA Ribonucleic acid
• Similar to a single strand of DNA
• Four different nucleotides make up organic bases
  except thymine is replaced with uracil
  (pyrimidine)

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DNA Structure
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Water

• Inorganic
• Stabilizes body temperature
• Protection
• Necessary for many chemical reactions of life
• Mixing Medium
• Mixture Substance physically but not chemically
  combined
• Solution Liquid, gas, or solid uniformly
  distributed
• Solvent What dissolves the solute
• Solute What is to be dissolved

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Acids and Bases Salts and Buffers

• Acid A proton donor or any substance that
  releases hydrogen ions
• Bases A proton acceptor or any substance that
  binds to or accepts hydrogen ions
• Salts A cation consisting of other than a
  hydrogen ion and other than an anion or hydroxide
  ion
• Buffers A solution of a conjugate acid-base pair
  in which acid and base component occur in similar
  concentrations

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The pH Scale

• Refers to the Hydrogen ion concentration in a
  solution
• Neutral pH of 7 or equal hydrogen and hydroxide
  ions
• Acidic a greater concentration of hydrogen ions
• Alkaline or basic a greater concentration of
  hydroxide ions

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Energy

• Energy The capacity to do work
• Potential Energy Stored energy
• Kinetic Energy Does work and moves matter
• Mechanical Energy Energy resulting from the
  position or movement of objects
• Chemical Energy Form of potential energy in the
  chemical bonds of a substance
• Heat Energy Energy that flows between objects of
  different temperatures

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Energy and Chemical Reactions
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Speed of Chemical Reactions

• Activation Energy Minimum energy reactants must
  have to start a chemical reaction
• Catalysts Substances that increase the rate of
  chemical reactions without being permanently
  changed or depleted
• Enzymes Increase the rate of chemical reactions
  by lowering the activation energy necessary for
  reaction to begin

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Activation Energy and Enzymes
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Cells The Fundamental Units of Life

• Cells are the basic structural and functional
  units of all forms of life.
• Prokaryotic cells (bacteria) lack a distinct
  nucleus.
• Eukaryotic cells (plants and animals) have a
  distinct nucleus.

Figure 2-6
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Animation Prokaryotic and Eukaryotic Cells
PLAY ANIMATION
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A human body contains trillions of cells, each
with an identical set of genes.
There is a nucleus inside each human cell (except
red blood cells).
Each cell nucleus has an identical set of
chromosomes, which are found in pairs.
A specific pair of chromosomes contains one
chromosome from each parent.
Each chromosome contains a long DNA molecule in
the form of a coiled double helix.
Genes are segments of DNA on chromosomes that
contain instructions to make proteinsthe
building blocks of life.
The genes in each cell are coded by sequences of
nucleotides in their DNA molecules.
Stepped Art
Fig. 2-7, p. 38
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• All Living Organisms are made up of
  Macromolecules
• Complex Carbohydrates
• Proteins
• Nucleic Acids
• Lipids

Figure 2-7
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States of Matter

• The atoms, ions, and molecules that make up
  matter are found in three physical states
• solid, liquid, gaseous.
• A fourth state, plasma, is a high energy mixture
  of positively charged ions and negatively charged
  electrons.
• The sun and stars consist mostly of plasma.
• Scientists have made artificial plasma (used in
  TV screens, gas discharge lasers, florescent
  light).

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Matter Quality

• Matter can be classified as having high or low
  quality depending on how useful it is to us as a
  resource.
• High quality matter is concentrated and easily
  extracted.
• low quality matter is more widely dispersed and
  more difficult to extract.

Figure 2-8
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CHANGES IN MATTER

• Matter can change from one physical form to
  another or change its chemical composition.
• When a physical or chemical change occurs, no
  atoms are created or destroyed.
• Law of conservation of matter.
• Physical change maintains original chemical
  composition.
• Chemical change involves a chemical reaction
  which changes the arrangement of the elements or
  compounds involved.
• Chemical equations are used to represent the
  reaction.

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Chemical Change

• Energy is given off during the reaction as a
  product.

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Types of Pollutants

• Factors that determine the severity of a
  pollutants effects chemical nature,
  concentration, and persistence.
• Pollutants are classified based on their
  persistence
• Degradable pollutants
• Biodegradable pollutants
• Slowly degradable pollutants
• Nondegradable pollutants

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Nuclear Changes in Atoms

• Natural radioactive decay unstable isotopes
  spontaneously emit fast moving chunks of matter
  (alpha or beta particles), high-energy radiation
  (gamma rays), or both at a fixed rate.
• Radiation is commonly used in energy production
  and medical applications.
• The rate of decay is expressed as a half-life
  (the time needed for one-half of the nuclei to
  decay to form a different isotope).

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Animation Positron-Emission Tomography
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Animation Half-Life
PLAY ANIMATION
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Nuclear Changes Fission

• Nuclear fission nuclei of certain isotopes with
  large mass numbers are split apart into lighter
  nuclei when struck by neutrons.

Figure 2-9
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Stepped Art
Fig. 2-6, p. 28
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Nuclear Changes Fusion

• Nuclear fusion two isotopes of light elements
  are forced together at extremely high
  temperatures until they fuse to form a heavier
  nucleus.

Figure 2-10
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Video Nuclear Energy
PLAY VIDEO

• From ABC News, Environmental Science in the
  Headlines, 2005 DVD.

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ENERGY

• Energy is the ability to do work and transfer
  heat.
• Kinetic energy energy in motion
• heat, electromagnetic radiation
• Potential energy stored for possible use
• batteries, glucose molecules

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Electromagnetic Spectrum

• Many different forms of electromagnetic radiation
  exist, each having a different wavelength and
  energy content.

Figure 2-11
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Electromagnetic Spectrum

• Organisms vary in their ability to sense
  different parts of the spectrum.

Figure 2-12
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Animation Visible Light
PLAY ANIMATION
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Relative Energy Quality (usefulness)
Source of Energy
Energy Tasks
Electricity Very high temperature heat (greater
than 2,500C) Nuclear fission (uranium) Nuclear
fusion (deuterium) Concentrated
sunlight High-velocity wind
Very high-temperature heat (greater than 2,500C)
for industrial processes and producing
electricity to run electrical devices (lights,
motors)
High-temperature heat (1,0002,500C) Hydroge
n gas Natural gas Gasoline Coal Food
Mechanical motion to move vehicles and other
things) High-temperature heat (1,0002,500C)
for industrial processes and producing
electricity
Normal sunlight Moderate-velocity
wind High-velocity water flow Concentrated
geothermal energy Moderate-temperature
heat (1001,000C) Wood and crop wastes
Moderate-temperature heat (1001,000C) for
industrial processes, cooking, producing steam,
electricity, and hot water
Dispersed geothermal energy Low-temperature heat
(100C or lower)
Low-temperature heat (100C or less) for
space heating
Fig. 2-13, p. 44
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ENERGY LAWS TWO RULES WE CANNOT BREAK

• The first law of thermodynamics we cannot create
  or destroy energy.
• We can change energy from one form to another.
• The second law of thermodynamics energy quality
  always decreases.
• When energy changes from one form to another, it
  is always degraded to a more dispersed form.
• Energy efficiency is a measure of how much useful
  work is accomplished before it changes to its
  next form.

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Mechanicalenergy(moving,thinking,living)
Chemical energy (photosynthesis)
Chemical energy (food)
Solar energy
Waste Heat
Waste Heat
Waste Heat
Waste Heat
Fig. 2-14, p. 45
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SUSTAINABILITY AND MATTER AND ENERGY LAWS

• Unsustainable High-Throughput Economies Working
  in Straight Lines
• Converts resources to goods in a manner that
  promotes waste and pollution.

Figure 2-15
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Sustainable Low-Throughput Economies Learning
from Nature

• Matter-Recycling-and-Reuse Economies Working in
  Circles
• Mimics nature by recycling and reusing, thus
  reducing pollutants and waste.
• It is not sustainable for growing populations.

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Inputs (from environment)
System Throughputs
Outputs (into environment)
Energy conservation
Low-quality Energy (heat)
Energy
Sustainable low-waste economy
Waste and pollution
Waste and pollution
Pollution control
Matter
Recycle and reuse
Matter Feedback
Energy Feedback
Fig. 2-16, p. 47
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Animation Economic Types
PLAY ANIMATION