Matter

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Matter Change
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What is Chemistry?

• The study of the composition, structure
  properties of matter the changes it undergoes

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Why Study Chemistry?

• To explain the natural world
• To prepare for a career
• To be an informed citizen

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The Scientific Method
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Mass vs. Matter

• Mass the measure of the amount of matter in
  something
• Matter anything that has mass and takes up
  space.

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Mass vs. Weight

• 1) Mass is a measurement of the amount of matter
  something contains, while weight is the
  measurement of the pull of gravity on an object.
• 2) Mass is measured by using a balance comparing
  a known amount of matter to an unknown amount of
  matter. Weight is measured on a scale.
• 3) The Mass of an object doesn't change when an
  object's location changes. Weight, on the
  otherhand does change with location.

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Atom vs. Element

• Atom the smallest unit of an element that
  maintains the properties of that element.
• Element pure substance made only of one kind of
  atom (found on the periodic table)
• You only need 1 atom to call matter an element

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What is a Compound?

• Compound is a substance that is made from the
  atoms of two or more elements that are chemically
  bonded.
• Ex H2O, glucose (C6H12O6), NaCl

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Classification of MatterPure Substances vs.
Mixtures

• All pure substances are either elements or
  compounds!!
• If you can write the chemical formula for a
  substance it is a pure substance
• Ex H2O, Ag (silver), CO2, Pb (lead)

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What is a Mixture?

• Mixture made up of two or more kinds of matter
  that retains its own properties and identity.
• You cannot write a chemical formula for a mixture
  
• Ex. Oil/water, pop, ketchup, air.

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Be Careful With Mixtures!

• You may write the chemical formula for the
  individual components of a mixture but not the
  mixture as a whole unit.
• Example Air (no chemical formula)
• Individual components include N2, O2, CO2

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Two Types of Mixtures

• Homogeneous same proportion of components
• It looks uniform/same throughout
• Ex. Salt water, milk (not spoiled!)
• Heterogeneous does not have the same proportion
  of components
• Can see more than one substance
• Ex. oil and water, granola bars

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Properties of all MatterExtensive vs. Intensive

• Extensive Property
• DEPENDS on the amount of matter that is present
  will change if amount of matter changes
• Examples volume, mass and energy
• - A pencil is 15 cm in length
• - The chemical reaction gave off 165 kilojoules
  of energy

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• Intensive Property
• DOES NOT depend on the amount of matter present
  and will not change if the amount of matter is
  changed
• Examples Color, Boiling/Freezing/Melting Points,
  Density, Malleability, Ductility
• - The color of the clown shoes are red
• - The density of water is 1 g/cm3 its bp is
  100C

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Quantitative vs. Qualitative Measurements

• Quantitative a description of a relevant
  characteristic that involves a numerical
  measurement
• Ex The bird has a wingspan of 2 meters
• Qualitative a description of a relevant
  characteristic that does not involve a numerical
  measurement
• Ex The bird has a long wingspan

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States of Matter

• Solid has definite size and shape, rigid, only
  vibrational movement of particles due to strong
  intermolecular (IM) forces and little space
  between them
• Liquid definite size, not a definite shape
  (takes the shape of the container its in), fluid
  movement due to weaker IM forces allows for more
  space between the particles
• Gas no definite size or shape (fills the
  container it is in), fluid, very energetic
  movement due to extremely weak IM forces and lots
  of space between them
• Plasma no definite size or shape like gases,
  very energetic, constant electron movement leads
  to charges matter, rarest phase of matter on
  earth but most abundant in universe

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Liquid Versus Aqueous

• Liquids are chemicals that are in the pure form.
• The only pure liquid that we work with in
  chemistry (unless otherwise noted by the teacher)
  is water, H2O.
• Aqueous solutions are homogeneous mixtures where
  water acts as a solvent.
• Examples include vinegar (HC2H3O2 in H2O), salt
  water (NaCl in H2O)

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States Of Matter Video

• https//www.schooltube.com/video/3b6ad2bcfbd9c8c76
  51a/
• https//www.youtube.com/watch?vbMbmQzV-Ezs

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Law of Conservation of Mass

• Mass is neither created or destroyed in chemical
  reactions
• The mass of a system may change state (liquid to
  gas) but is never lost in ordinary chemical
  reactions
• For this law to be tested properly a closed
  system must be used

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Physical Properties

• Physical Properties are a characteristic feature
  of a sample that can be observed or measured
  without changing the identity of the substance
• Examples Melting/freezing/boiling points,
  conductivity, malleability, density, color,
  hardness, texture, taste, smell, viscosity

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Chemical Properties

• Chemical Properties are a characteristic feature
  that relates to a substances ability to undergo
  changes that transform it into another/different
  chemical
• To identify this type of property, a chemical
  change must be performed
• Examples Reactivity, Flammability, new color,
  new smell

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Chemical Change

• A Chemical Change is a change in which one or
  more substances are converted into different
  substances
• A log burning or iron rusting
• MAKING COOKIES

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Indicators of a Chemical Change

• Color change
• Precipitation formed (ppt.) when 2 transparent
  liquids mix and a solid is formed
• Gas production (fizzing, bubbling)
• Odor change
• Explosion, flame or light production
• Thermal change when no outside energy is added or
  subtracted from the system

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Physical Change

• A physical change is a change in the substance
  that DOES NOT involve a change in the identity of
  the substance
• Examples Cutting Hair or melting snow (all
  changes of state are physical changes)

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Phase changes are considered physical changes.
(No new substances are being formed.)

• Melting solid to a liquid
• Freezing liquid to a solid
• Boiling liquid to a gas
• Condensation gas to a liquid
• Evaporation liquid to a gas
• Sublimation solid to a gas
• Deposition gas to a solid

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Property vs. Change Examples

• The pencil is 15 cm in length (property)
• The pencil is cut in half and each piece is now
  7.5 cm in length (change)
• The color of phenolphthalein is clear (property)
• Phenolphthalein is reactive in basic solutions.
  (property)
• The color of phenolphthalein changed from clear
  to magenta when placed in ammonia (change)