Obj 4: Properties of Matter

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Obj 4 Properties of Matter

• Vocabulary is EVERYTHING!
• Density Buoyancy Viscosity Periodic Trends
  Ionic Covalent Metals Nonmetals Metalloids
  Valence Electrons Protons Neutrons Electrons
  Acids Bases Salts Elements Compounds
  Mixtures Chemical change Physical change Law
  of conservation of Mass solid Liquid Gas
  Oxidation Digestion Universal Solvent Solute
  Saturated Unsaturated Supersaturated Anion
  Cation pH neutralization reaction

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Density

• This is the amount of matter in a given volume.
• Density mass/volume
• DM/V
• You will need to solve for the other parts of
  this formula so
• Mass denisty x volume M D x V
• Volume Mass/ Density V M/D

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Viscosity

• The resistance of fluid to flow.
• Think of Slower than molasses in January
  molasses is a very thick substance, when you
  chill it, it flows even slower. It has higher
  viscosity.
• Usually, the more dense a fluid is, the higher
  its viscosity.

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Buoyancy

• The tendency of a less dense substance to float
  on top of a more dense substance
• If an object sinks, its gravitational force is
  greater than the buoyant force of the water
• If an object floats, its gravitational force is
  less than its buoyant force.

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Types of Matter

• Elements are substances that consist of only one
  type of atom. They cannot be broken into any
  other atoms. They are pure substances and
  areAlways Homogeneous!
• Examples Copper Lead Gold Silver
• Mixtures a combination of more than one
  substance, each substance retaining its own
  properties. Mixtures can be physically separated
  by Filtering evaporation distillation
• Examples Salt Water birdseed chicken soup
• Heterogeneous Mixtures that have physically
  different parts
• Homogeneous Mixtures that appear to be the same
  throughout
• Compounds is a substance that contains more than
  one type of element and can only be broken apart
  by chemical reactions. Always homogeneous
• Examples H2O NaCl MgSO4

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The Periodic Table Label your table!!!

• Elements are grouped as metals non-metals and
  metalloids
• Elements in the same group have similar physical
  properties
• Elements in the first group are called Alkali
  Metals
• Elements in the second group are called Alkali
  Earth Metals
• Elements in groups 3-12 are called Transition
  Metals
• Elements in group 17 are called the Halogens
• Elements in group 18 are called Noble Gases
• Elements at the bottom of the table are called
  the Lanthanide Series and the Actinide Series
• Atomic Sizes of element increase as you move down
  the table and decrease as you move across

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Bonding

• Ionic Bonds form between a metal and a non-metal
  when one atom transfers its electron to another
  atom.
• Covalent bonds occur between two non metals when
  electrons are shared so that each fulfills its
  octet
• Metallic Bonds are formed between two metals and
  all electrons are shared surrounding the nucleii

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Balancing Chemical Equations

• Law of Conservation of Mass Mass can neither be
  created, nor destroyed or the mass of the
  reactants must equal the mass of the products
• Balanced Equations to balance an equation,
  coefficients must be placed in front of (not
  behind) compounds to ensure that the same numbers
  and types of elements are present on each side of
  the reaction

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• Try the problems

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Changes in Matter

• Chemical Changes elements recombine to form new
  chemical compounds with new and different
  properties.
• Physical changes the form of a substance may
  change but its chemical make-up doesnt change,
  no new substance is made.

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What processes are Physical changes?

• Melting change from solid to liquid
• Evaporating change from liquid to gas
• Condensing change from gas to liquid
• Freezing change from liquid to solid.
• Dissolving particles spread out evenly in the
  substance that dissolves it.
• IN ALL OF THESE PROCESSES THE PARTICLES CHANGE
  FORM BUT NO NEW SUBSTANCE IS MADE!!!!!!!

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Changes of State are physical changes

• Solid to Liquid melting
• Liquid to Gas evaporating
• Gas to Liquid condensing
• Liquid to solid freezing
• The molecules in the substance become either more
  energized or less energized BUT NO NEW SUBSTANCE
  IS FORMED!
• This is not a chemical change!!!!!

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So. Then what are Chemical Changes?

• Burning makes carbon dioxide, new substance
  formed.
• Bubbles indicate a gas is forming, like when
  baking soda bubbles when vinegar is added to it.
  A strong odor is another indication of a gas
  forming.
• There is a temperature change, this indicates
  that heat is given off or given is absorbed,
  exothermic and endothermic processes.
• When two clear liquids are mixed and a cloudy
  white precipitate forms at the bottom of the
  beaker. A solid is formed.

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Digestion and Oxidation

• Another type of chemical reaction.
• Your digestive system physically and chemically
  changes food into smaller molecules that cells
  can use.
• The physical process is chewing
• The chemical processes are saliva chemically
  breaks down the food particles glands break down
  the food particles gastric juices in the stomach
  break into proteins which also are broken down.
  The chemical process continues all the way
  through the intestine to give your body the
  energy it needs.

• Oxidation is also another type of chemical
  reaction
• Electrons are transferred to form new substances
• One substance has to lose the electrons and one
  substance has to gain them.

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Physical changes in the rock cycle

• Weathering wind water and gravity break up rock
• Erosion broken up pieces of rock are transported
  by wind, water, or ice and deposited elsewhere
• Sedimentary rock is composed of cemented
  fragments of these rocks
• Metamorphic rock is formed when heat and pressure
  chemically change physical properties of igneous
  rock.
• Igneous rock is rock that is melted and then
  refrozen into a solid .

Metamorphic rock is the only rock that is
chemically changed!!!!
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Try the problems.
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WATER

• Physical States water can be in three states, S,
  L, G within earths temperature range
• Density water is unusual because it expands and
  becomes less dense when it is frozen.
• Specific Heat the amount of energy it takes to
  raise the temperature of 1 kg of water 1 C
• Universal solvent one of waters most important
  properties is its ability to dissolve other
  substances. Water is highly polar and dissolves
  most other polar substances

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POLAR!?!?

• Water is a polar molecule, this is a molecule
  that has partial positive and negative charges.
• Universal Solvent Water is an extremely
  effective solvent because it dissolves other
  substances to make solutions.

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Solubility

• Refers to the greatest amount of solute that a
  solvent will dissolve before the solution becomes
  saturated
• Temperature
• Solubility of solids generally increase as
  temperature increases
• Solubility of gases generally decrease as
  temperature decreases

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Dissolving, how can we speed it up?

• We can increase surface area, this is the amount
  of exposed surface
• Stirring or shaking will all more solute to
  spread out into the solution.
• By far, the best method to increase dissolving is
  to increase temperature. This increases the
  kinetic energy of the molecules and increases
  spreading of the solute.

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Acids and Bases

• Acids are substances that react with water to
  form hydrogen ions, H.
• Indicators are substances that changes color in
  the presences of an acid or a base.
• pH paper will turn red in an acid.
• Bases are substances that contain OH- ions.
• Bases turn pH paper blue.

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pH Scale

• Acids have a pH that is less than 7
• Bases have a pH that is greater than 7
• Neutral substances like water have a pH of 7
• The pH scale measures the exponential value of
  the H
• Acids are added to bases in a neutralization
  reaction to form water and a salt
• Never add water to an acid, only acid to water.

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Try the last set of problems