Physical Science

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Physical Science Notes

• Atomic Theory
• Two schools of thought developed over mental
  pictures or models of the nature of matter some
  2,500 years ago in ancient Greece.
• One school of thought said matter was continuous
  and could divide forever.
• The other school of thought said that matter
  could only be divided down to the atom and then
  no longer be divided.
• Both of these arguments were hypothetical because
  there was no evidence to back up the two schools
  of thought.

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Physical Science Notes

• John Dalton
• This English chemist carried out numerous
  experiments in which elements reacted to form
  compounds.
• He noticed that the masses of many elements
  combined to form products in simple whole number
  ratios like 11, or 12, or 23.
• Dalton ended up forming a model of the atom even
  though he could not see it or touch it directly.
• In 1803 he published his atomic theory of matter
  which stated...

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• Elements are composed of particles called atoms,
  which are indivisible and indestructible.

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Physical Science Notes

• John Dalton
• Things to remember about the atomic theory of
  matter
• Atoms of the same element are alike in mass
• Atoms of different elements differ in mass
• Compounds are formed by the joining of atoms of
  two or more elements in definite whole-number
  ratios.
• Hundreds of compounds could be formed by
  combining atoms of different elements.
• A good example of this atomic ratio would be
  water (H2O), here there are two hydrogen atoms
  for every one oxygen atom.

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Physical Science Notes

• John Dalton
• However there were errors in Daltons theory.
  His model of the atom as a solid unchanging
  particle no longer agreed with the new evidence
  found in the early 1900s
• Atoms of uranium were found to be radioactive and
  emitted powerful electromagnetic waves. This
  implied that atoms were not indivisible but
  contained particles smaller than themselves.
  Also, radioactive elements would decay into
  lighter elements.
• Isotopes were discovered these were atoms of the
  same element but with different masses.

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J. J. Thomson

• Through his study of cathode rays he concluded
  that these rays were made of negatively charged
  particles called electrons and that all atoms
  contained electrons.

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Physical Science Notes

• Radical Revision...
• Ernest Rutherford performed his famous gold
  leaf experiments
• He took the radioactive element polonium which
  emits alpha particles.
• These alpha particles contain two protons and two
  neutrons (but he did not know at the time that
  the neutron existed).
• He thought that these alpha waves would go
  straight through a thin gold piece of foil.
• But what he observed was that some of these alpha
  particles bounced straight back as if they hit a
  brick wall.

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Physical Science Notes

• Radical Revision...
• Plum pudding (JJ Thomsons model) does not allow
  particles to bounce back very well.
• Rutherford gave his atomic model a positive core
  with a dense nucleus, which would explain why
  some alpha particles would bounce back (like
  hitting a brick wall) when they came in contact
  with the nucleus.
• He hypothesized that the electrons circled the
  nucleus like tiny planets. The electrons like
  charges kept them separated as they orbited the
  nucleus.
• Rutherfords view of the atom became the
  planetary model of the modern atom.
• But it did not last long because of new facts
  that were ready to be uncovered.

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Physical Science Notes

• Radical Revision...
• Niels Bohr (Danish physicist) comes along and
  places these orbiting electrons into different
  energy levels or shells. However, even among the
  many energy levels the electrons are constantly
  shifting from one energy level to the next.
• As a result of this uncertainty of electron
  position at any given time, we now use the
  current concept of an electron cloud model for
  the atom.
• The lower the energy level the more attracted the
  electron was to the nucleus.
• The farther out you travel in the energy levels
  (the cloud) the more energy those outer shell
  electrons are going to have so these higher
  energy levels can hold more electrons.

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Physical Science Notes

• Radical Revision...
• If you looked at energy levels and the max number
  of electrons they can hold it would be like this
• Energy Level 1 holds 2 electrons
• Energy Level 2 holds 8 electrons
• Energy Level 3 holds 18 electrons
• Energy Level 4 holds 32 electrons
• When an electron absorbs energy it jumps to a
  higher energy level and when an electron emits
  energy it is getting closer to the nucleus.

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EMITS ENERGY
ABSORBS ENERGY
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Physical Science Notes

• What is 2n 2...
• In this formula the n represents the level
  number. So, if you plug in the level number you
  will know the max number of electrons you can put
  into that particular energy level or energy
  shell.
• For example
• For energy level 2 you can figure out the max
  number of electrons that will fit into that level
  by solving the formula
• 2 n 2 2 (2) 2 8 electrons max

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Physical Science Notes

• Model of the atom is still changing...
• Even now some physicists hypothesize that the
  nucleus is also structured in energy shells and
  predict that radioactive atoms have unstable
  shell structures.

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Physical Science Notes

• Atomic Structure
• The modern atomic model shows how the subatomic
  particles in every atom are arranged in a
  systematic structure that explains their physical
  and chemical properties.
• The basic building block of matter is the atom
  it is the smallest unit of an element that still
  has the chemical properties of that element.
• An element is any substance made up of only one
  type of atom.
• Only 92 of these elements are stable enough to
  exist on Earth or in stars. The most current
  number of elements is 117.

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Physical Science Notes

• Atomic Structure
• Atoms have three major subatomic particles
• Protons have a _________ charge and are found in
  the _________.
• Neutrons have a ________ charge and are found in
  the __________.
• Electrons have a __________ charge and are found
  in the ________ cloud outside of the __________.

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Physical Science Notes

• Atomic Structure
• Protons and neutrons have about the same mass.
• The mass of electrons is too small to count in
  the total mass of an atom.
• Protons and neutrons have a relative mass of 1
  atomic mass unit (amu).
• Electrons have a relative mass of 0 amu.
• The number of protons and electrons are always
  equal in an electrically neutral atom.

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Physical Science Notes

• Atomic Structure
• The electrons do not fly apart because of the
  electrical attractive force between the nucleus
  and the electron cloud.
• A nuclear binding force counteracts the protons
  electrical repulsion and holds the nucleus
  together. Scientists believe this force may be a
  function of the neutrons.
• Electrons in higher orbits are full of energy and
  are less stable.
• The volume of the electron cloud is what
  determines the volume of an atom.

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Physical Science Notes

• Atomic Structure
• The identity of an element is determined by the
  number of protons which are found in the nucleus
  of an atom.
• When an atom rearranges its electrons the element
  itself does not change because you have not
  changed the protons.
• When atoms of different elements combine to form
  compounds, they do so by sharing, donating, or
  capturing unstable electrons in higher energy
  levels.

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Physical Science Notes

• Atomic Structure
• The atoms of an element with different numbers or
  neutrons are called isotopes.
• If you are a stable isotope, then your nucleus
  does not decay and emit radioactive energy
  particles.
• So, an unstable isotopes nucleus does decay and
  emit radioactive particles.

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Physical Science Notes

• Atomic Structure
• The atomic number is equal to the number of
  protons in that element.
• The atomic mass is the elements weighted average
  of its isotopes masses and usually has a decimal
  remainder.
• The mass number (A) of an atom is equal to the
  sum of protons (Z) and neutrons (N) so, A Z
  N.
• To determine the number of neutrons in an element
  of an atom you have to rearrange the formula N
  A Z
• The mass number is not on the periodic table and
  must be given to determine the number of neutrons
  in a particular isotope of an element.
• To write an isotopes symbol you must have its
  name (symbol), atomic number, and mass number.

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Physical Science Notes

• Physical Properties of Matter
• Define matter ___________________
• A physical property is something you can observe
  or measure with a tool without changing the
  composition of the substance.
• A physical change is any change in a substances
  size, shape, color, or phase (solid, liquid, or
  gas) that does not change the composition of the
  substance.

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Physical Science Notes

• Physical Properties of Matter
• Examples of physical properties
• Boiling or condensing point, melting or freezing
  point, density, solubility, viscosity, and
  thermal or electrical conductivity
• Examples of mechanical properties
• Tensile and compressive stress, elasticity,
  plasticity, hardness, and toughness
• Remember these properties can be affected by a
  rise or fall in temperature.

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Physical Science Notes

• Physical Properties of Matter
• A phase change is known as a physical change
  because the composition of the substance has not
  been altered. Water can be used as a great
  example of a phase change.
• Density is a physical property so do not forget
  the formula D m / V.

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Physical Science Notes

• Physical Properties of Matter
• Solubility is the maximum amount of solute that
  will dissolve in a given solvent under normal
  conditions.
• The solute is the substance that dissolves, and
  the solvent is the dissolving substance.
• A solute and solvent together make up a solution.

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Physical Science Notes

• Physical Properties of Matter
• When you can not dissolve any more solute within
  the solvent then you have a saturated solution.
• An unsaturated solution is just the opposite.
• Water is the universal solvent because so many
  substances readily dissolve in it.

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Physical Science Notes

• Physical Properties of Matter
• Viscosity is a measure of a fluids resistance to
  flow.
• High viscosity takes longer to pour than low
  viscosity. Syrup will have a higher viscosity
  than water.
• Remember temperature can change a fluids
  viscosity.

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Physical Science Notes

• Physical Properties of Matter
• Conductivity is a measure of a materials ability
  to conduct or move electrical current.
• In a solution you can conduct electrical current
  but it depends on the solute.
• These solutes that conduct electricity in a
  solution are called electrolytes.

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Physical Science Notes

• Physical Properties of Matter
• Think of a mixture as a soft drink or a pizza.
  These two items are made up of two or more
  substances and can be separated by physical
  means.
• A chemical compound is not a mixture because the
  proportions of substances are not the same all
  the time. Think about making a pizza.

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Physical Science Notes

• Physical Properties of Matter
• A pizza is a heterogeneous mixture because you
  can distinguish among the different materials it
  took to make the pizza.
• A 2 liter soft drink is a homogeneous mixture
  because the water, gas, sugar, and flavoring in
  the drink are blended evenly throughout.
• Also, we can refer to a homogeneous mixture as a
  solution.

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Physical Science Notes

• Physical Properties of Matter
• A colloid is a type of solution whose particles
  will not settle out if the solution is left
  standing. The word colloid comes from the Greek
  word for glue.
• Examples of colloids can be fog (liquid water
  suspended in air) and smoke (solids suspended in
  air from the fire).
• One way to distinguish a colloid from a solution
  is by its appearance. A beam of light is
  invisible as it passes through a solution but can
  readily be seen as it passes through a colloid.
• The scattering of light by colloid particles is
  called the Tyndall effect.

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Physical Science Notes

• Physical Properties of Matter
• A suspension is a heterogeneous mixture
  containing a liquid in which visible particles
  settle out. Think of pond water.

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Physical Science Test Review

• 1. Substances are either elements...
• 2. Odor is a...
• 3. What type of mixture is a fruit salad...
• 4. Homogenous mixtures can be separated...
• 5. Breaking glass is a...
• 6. What type of mixture is a suspension...
• 7. What type of property is color...
• 8. What type of change is freezing water...
• 9. A colloid is a...
• 10. Law of conservation of mass...
• 11. What is smoke (think glue)...
• 12. A mixture can be separated...
• 13. Is mass lost when a firecracker explodes...

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Physical Science Test Review

• 1. Know some examples of a physical change.
• 2. Smoke is an example of...
• 3. Know what the Tyndall effect is...
• 4. Which one is not homogeneous...
• 5. What is a mixture...
• 6. The other name for a homogeneous mixture...
• 7. What happens when gasoline is burned in an
  engine?
• 8. What is steam?
• 9. The color of ink...
• 10. The particles that make up all matter...

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Physical Science Test Review

• 11. Matter is classified as...
• 12. When you mix sugar and sand...
• 13. A solid changing directly to a gas...
• 14. A diamonds ability to resist corrosion is...
• 15. A type of air pollution that is a colloid...
• 16. What type of mixture is a colloid?
• 17. The law that describes the relationship
  between the mass of a substance before and after
  a physical or chemical reaction is...
• 18. Remember what the dots and the models
  represent...watch the overhead!

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Physical Science Notes

• Metals
• Metals are found on the left in the periodic
  table.
• Metals are good conductors of heat and
  electricity.
• Metals are all solid at room temperature except
  for one, which one would that be ___________?
• Metals reflect light so we say they have a
  luster.
• Metals are also malleable (hammered or rolled
  into sheets) and ductile (drawn into wires)

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Physical Science Notes

• Metals and Ionic bonding
• Metals generally have 1-3 electrons in their
  outer energy levels so they tend to give up
  electrons easily.
• When a metal combines with a nonmetal the metals
  tend to lose electrons to the nonmetals and form
  what we call an ionic bond.

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Physical Science Notes

• Metals and Metallic bonding
• Another way metals bond is called metallic
  bonding. This type of bonding helps to explain
  why you can hammer a metal (malleability) into
  thin sheets or draw metal (ductility) into a
  wire.
• This metallic bonding allows the electrons in
  metals to move freely past one another without
  losing their bond to the nucleus.
• The ability of these electrons to move around
  allows metals to conduct electricity and heat.

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Physical Science Notes

• Covalent bonding
• Some atoms of nonmetals are unlikely to lose or
  gain electrons.
• For example the elements in Group 14 have four
  electrons in their outer energy levels.
• These elements have to lose or gain electrons to
  become stable, BUT there is an easier way...They
  can share electrons!
• This sharing of electrons is known as covalent
  bonding.

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Physical Science Notes

• Alkali Metals
• The alkali metals are in Group 1. They are
  softer then most other metals and they can react
  violently with oxygen and water.
• In nature we do not see these elements by
  themselves and they are usually stored in an
  unreactive substance such as oil.
• They are so reactive because they have only one
  electron in their outer energy level. When this
  electron is given up the alkali metal becomes a
  positively charged ion. This happens in the
  compounds NaCl and KBr.
• Name the alkali metal that is radioactive and
  very rare ___________________.

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Physical Science Notes

• Alkaline Metals
• The alkaline metals make up Group 2. They have 2
  electrons in their outer energy level so they
  combine readily with other elements.
• They also are not found as free elements in
  nature.
• Name two alkaline earth metals we see used on a
  certain national holiday. __________ __________
• Name three other ways we use magnesium metal.
• 1.
• 2.
• 3.

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Physical Science Notes

• Alkaline Metals
• How are plants related to magnesium?
  __________________________________________________
  __________
• Name three ways alkaline earth metals can be
  related to your body
• 1.
• 2.
• 3.

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Nucleus
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Neutron
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Groups or Families
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Electron Cloud
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Chlorine Cl
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Eight
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Isotope
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Metals
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Decreases
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Physical Science Test Review

• 1. Weighted mass of the mass numbers of all the
  isotopes...
• 2. Seven electrons in the outermost energy
  level...
• 3. The number of protons...
• 4. Each energy level holds a max number of...
• 5. Calculate mass number...
• 6. What subatomic particle moves around the
  nucleus?
• 7. Different numbers of neutrons...
• 8. Horizontal rows...
• 9. A chemical symbol...
• 10. Quarks...
• 11. Groups 3-12...
• 12. Electron dot diagrams...
• 13. Complete a table, might want to watch this...

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Physical Science Chemical Symbol Test

• 1. Be ______ 14. Ne ______
• 2. Sulfur ______ 15. Si ______
• 3. N ______ 16. B ______
• 4. Vanadium ______ 17. Cr ______
• 5. Titanium ______ 18. Al ______
• 6. Sc ______ 19. Zinc ______
• 7. Manganese _____ 20. Germanium_____
• 8. P ______ 21. Arsenic ______
• 9. Argon ______ 22. Lithium ______
• 10. C ______ 23. Ga ______
• 11. Copper ______ 24. Ni ______
• 12. Mg ______ 25. Lead ______
• 13. Cobalt ______

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Physical Science Chemical Symbol Test

• 26. Silicon ______ 39. Uranium ______
• 27. Br ______
• 28. Calcium ______
• 29. Chlorine ______
• 30. F ______
• 31. He ______
• 32. Hydrogen ______
• 33. Fe ______
• 34. Mercury ______
• 35. Oxygen ______
• 36. K ______
• 37. Sodium ______
• 38. Se ______

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Physical Science Notes

• Transition Metals
• The biggest family of all are the transition
  metals.
• We find these in groups 3-12.
• When you include Group 1 (alkali metals) and
  Group 2 (alkaline metals), more than 75 of the
  elements in the periodic table are metals.
• Remember the most reactive metals are located at
  the bottom of their group.

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Physical Science Notes

• Non-Metals
• Non-metals are generally dull in appearance,
  usually brittle, and poor conductors of heat and
  electricity.
• Many non-metals are gases at room temperature.
  These include nitrogen, oxygen, fluorine,
  chlorine, and the noble gases. One non-metal,
  bromine, is a liquid at room temperature.
• The non-metals include all the elements in groups
  17 and 18 and some of the elements in groups 14,
  15, and 16 located above or to the right of the
  stair step line.
• The most reactive non-metals are at the top of
  their groups.

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Physical Science Notes

• Metalloids
• Metalloids have some characteristics of metals
  and non-metals and are semi-conductors of
  electricity.
• The metalloids border the step-like line near the
  right side of the periodic table in groups 13,
  14, 15, and 16.
• The elements that are categorized as metalloids
  are boron, silicon, germanium, arsenic, antimony,
  and tellurium.

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Physical Science Notes

• Energy levels and the periodic table
• The number of energy levels found within an
  element is equal to the period number in which
  the element is found.
• For example, the two elements in the first period
  have one energy level and the elements found in
  the second period have two energy levels.
• The atomic radius also increases as you go down a
  group and add another energy level.
• As you go across a period the atomic radii are
  greatest in the middle of the row and smallest at
  either end.
• We know that electrons in the outer energy level
  form chemical bonds with other atoms. We call
  these electrons valence electrons.

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Physical Science Notes

• Inorganic compounds
• Inorganic compounds contain few or no carbon
  atoms bonded to one another or to hydrogen.
• Most of these compounds are formed when a metal
  is bonded to a non-metal, such as NaCl (table
  salt).

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Polyatomic Ions
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Physical Science Notes

• Polyatomic Ions
• Clusters of different atoms can combine to form a
  charged particle that is called a polyatomic ion.
  
• This cluster stays together as a group when it
  combines with other atoms to form ionic
  compounds.
• A positively charged polyatomic ion acts like a
  metal and will combine with a non-metal.
• A good example of this is NH4, the ammonium ion.
• It has a 1 charge because it is short one
  electron and so it acts like a metal.

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Physical Science Notes

• Polyatomic Ions
• Now, if you have a sulfate ion, SO42-, it has a
  negative 2 charge because it has two extra
  electrons.
• When you combine the ammonium ion and the sulfate
  ion what ratio would have to exist?
  _______________

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• When writing an ionic formula between a metal and
  a nonmetal follow these 5 steps
• Write the symbols for the metal and the
  nonmetal.
• Write the valences as superscripts above each
  symbol.
• Drop the and - sign.
• Crisscross the valences so they become the
  subscript for the other element.
• Reduce subscripts whenever possible. Only when
  both are divisible by a number greater than one.

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Physical Science Notes

• Law of Conservation of Matter
• In any chemical equation, the products contain
  all of the atoms that were in the reactants, but
  the atoms are rearranged in new ways.
• A chemical reaction changes the ways atoms are
  grouped or arranged.
• Law of conservation of matter states that matter
  is neither created nor destroyed.
• In order to verify that a chemical equation for a
  reaction obeys the law of conservation of matter,
  it has to be a balanced equation.
• Each side of the equation must have the same
  number of atoms of each element.

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Physical Science Notes

• Steps to balancing a chemical equation
• Step 1 Count the number of atoms of each
  element in the reactants and products.
• Step 2 Balance the elements one at a time, by
  using coefficients.
• When no coefficient is written, it is assumed to
  be 1.
• Never balance an equation by changing subscripts.
• Make sure all coefficients are in the lowest
  possible ratio.

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Physical Science Notes

• Types of chemical reactions
• Single replacement reaction
• A BC ? B AC
• When one element replaces another element
• Double replacement reaction
• AB CD ? AC BD
• When an acid is neutralized by a base.
• Synthesis reaction
• A B ? AB
• Charcoal grill burning
• Decomposition reaction
• AB ? A B
• The electrolysis of water

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Physical Science Notes

• Chemical Change Indicators
• Examples of chemical properties are oxidation,
  burning, and corrosion. Remember in chemical
  changes new substances are formed.
• Oxidation
• Substances combine with oxygen, or other
  substances, by donating electrons to oxygen or
  the other substances.
• A great example of an oxidation reaction is the
  production of water. Here the properties of
  water are very different from the properties of
  hydrogen and oxygen.
• Burning or Combustibility
• These are special oxidation cases where a
  substance has the potential to combine rapidly
  with oxygen and burn. Huge amounts of energy in
  the form of heat and light are released.
• Corrosion
• Chemical changes that weaken or discolor useful
  metals. An iron nail combining with oxygen in
  the air will form rust.

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Physical Science Notes

• Chemical Change Indicators
• Precipitate
• A solid that forms when two liquids are mixed. A
  good example is when silver nitrate is mixed with
  a solution of sodium chloride (salt water). A
  white precipitate silver chloride is formed in
  the process of mixing.

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Physical Science Notes

• Chemical Changes Changes in Energy
• Exothermic reaction
• Energy is released during a chemical reaction
• It can be really intense when the energy is
  released and you will have light
• A good example is when a substance combusts or
  burns
• This energy comes from potential energy stored in
  the electron bonds
• It takes activation energy to break the
  electrons bonds and allow these electrons to
  rearrange themselves
• Products are more stable than the reactants

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Physical Science Notes

• Chemical Changes Changes in Energy
• Endothermic reaction
• Absorbs energy during a chemical reaction
• It needs a constant input of energy to activate
  the reactants and complete the reaction.
• Products are less stable than the reactants.

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Activation Energy
Energy
Energy Produced
Chemical Energy of Reactants
Chemical Energy of Products
Time
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Chemical Energy of Products
Activation Energy
Energy
Energy Absorbed
Chemical Energy of Reactants
Time
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pH Scale

• pH
• When the H ions increase the OH- ions decrease.
• When a solution reaches a pH of 7, then the
  number of H ions equals the number of OH- ions.
  We call this neutral.
• The more H ions you have the more acidic.
• The more OH- ions you have the more basic or
  alkaline.

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Physical Science Notes

• Kinetic Theory of Matter
• This theory states that particles of matter are
  in constant random motion and is used to explain
  how solutions are formed.
• For example
• In a solution of salt water, water molecules are
  constantly moving past each other while the
  crystals of salt are held together by ionic
  bonds.
• As time passes, the salt crystals are gradually
  pulled away from each other because water has
  electrical polarity.
• This polarity allows water to be a good solvent
  for both ionic compounds and for covalent
  compounds. Water is the universal solvent.

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Physical Science Notes

• Electrical Conductivity of Solutions
• Pure water is not a good conductor of
  electricity. Pure NaCl is not a good conductor
  of electricity. HOWEVER, salt water is good
  conductor of electricity because dissolved ionic
  solutes allow charged particles to flow easily in
  a liquid solution.

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Physical Science Notes

• Four Factors that affect dissolving rate
• Temperature Raising the temperature increases
  the rate because the particles are moving faster.
• Increase in surface area The smaller the size
  of the solute particles the greater the surface
  area exposed so the dissolving rate increases.
• Stirring Solvent molecules collide with the
  surface area of the solute more frequently so
  again the rate increases.
• Concentration The rate of dissolving decreases
  as a solution becomes more concentrated.

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Physical Science Notes

• Concentration
• The concentration of a solution is a ratio of the
  amount of solute dissolved per quantity of
  solvent.
• For example
• If you dissolve 10g of sodium chloride into 100g
  of water, then you have made a 110, or a 10
  percent solution, of sodium chloride.

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Physical Science Notes

• Solubility Graph The greater the slope the
  greater the response.

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Physical Science Notes

• Concentration Vocabulary
• Unsaturated A solution that can still hold more
  solute.
• Dilute A solution that can dissolve many times
  more solute than is already in the solution.
• Concentrated A solution that holds close to the
  max amount of solute that can be dissolved in the
  solution.
• Saturated A solution that holds the maximum
  amount of solute that can be dissolved.
• Supersaturated An unstable solution where the
  solutes can dissolve beyond their limits within
  the solution.

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Physical Science Nuclear Notes

• Nuclear Fusion Coming together

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Physical Science Nuclear Notes

• Nuclear Fission Splitting

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Physical Science Nuclear Notes

• Chain reaction The cascade of continuing
  nuclear fission (splitting) reactions.
• Critical mass The minimum mass required for a
  chain reaction to occur.
• Radioactivity The release of subatomic
  particles and powerful energy due to the
  spontaneous disintegration of unstable nuclei in
  the atoms of certain elements.
• Half-life
• The time required for half of it to decay
• For example
• Half life of C-14 is 5730 years. So it takes
  5730 years for half of it to decay.
• ½ to ¼ to 1/8 to 1/16 is the fraction of decay
  from the original mass.

115
Physical Science Nuclear Notes

• Decay When an unstable radioactive element
  transforms into an element or elements with a
  lower mass and releases and alpha or beta
  particle from its nucleus.
• Alpha Particle
• Has a mass of 4 amu and a charge of 2
• Symbol is 4He2.
• Atomic number decreases by 2
• Mass decreases by 4
• Beta Particle
• It is an electron
• Has an insignificant mass
• Has a charge of -1
• Symbol is 0e-1
• Mass stays the same but atomic number increases
  by 1
• Gamma Ray
• Powerful electromagnetic wave
• Short wavelength and very high frequency
• Can penetrate 2 to 3 cm of lead
• However does not transform unstable elements into
  other elements or alter their mass

116
Physical Science Nuclear Notes
117
Physical Science Nuclear Notes
Paper
Aluminum
Thick Lead or Concrete
118
Physical Science Nuclear Notes

• Alpha decay

119
Physical Science Nuclear Notes

• Uranium Disintegration Series
• Mass and charge are CONSERVED
• Alpha particle decay
• 238U92 ? 234Th90 4He2
• Beta particle decay
• 234Th90 ? 234Pa91 0e-1

Notice the relationship between the particle and
the transformed element.
120
Physical Science EOC

• Today is the LAST FULL DAY to ask questions in
  regard to the EOC.
• I will be here in the afternoons all week for EOC
  Review and make-up days.
• Tomorrow between 1155 and 1220 you will be
  turning in Physical Science books. The cost of a
  book is 55.21.
• The Physical Science EOC is Wednesday, June 4th
  from 815 1050. You have as much time as you
  need on the EOC so do not rush.