Steps of the scientific method

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Steps of the scientific method

1. Make an OBSERVATION
2. Formulate a question
3. Do research
4. Form a Hypothesis
5. Test the Hypothesis
6. Analyze results
7. Draw conclusions
8. Share with others

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DEMONSTRATION QUESTIONS

• WHAT ARE THE TWO LIQUIDS IN THE BEAKERS?
• WHAT WOULD BE A HYPOTHESIS FOR THIS EXPERIMENT?
• HOW CAN WE TEST OUR HYPOTHESIS?
• WHAT CONCLUSION CAN BE DRAWN FROM THIS
  DEMONSTATION?

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Units of Measurement

• SI units base units

Length Meter M
Mass Kilogram Kg
Time Second S
Temperature Kelvin K
Electric current Ampere A
Amount of Substance Mole Mol
Luminous intensity Candela cd
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SI PREFIXES
Giga G Billion 1000 000 000
Mega M Million 1000 000
Kilo K Thousand 1000
hecto h hundred 100
deca da tens 10
Base unit 1
Deci d Tenth 0.1
Centi c Hundredth 0.01
Milli m Thousandth 0.001
Micro , Millionth 0.000 001
Nano N Billionth 0.000 000 001
pico p trillionth 0.000 000 000 001
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PRACTICE CONVERSIONS

• 113 g to milligrams
• 700 micrometers to nanometers
• 49,890 m to centimeters

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What is chemistryThe study of matter and how
it changes

• Example of chemistry
• soap food, glass
• Because of what it is made of or how it changes

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What is matter?

• Anything that has mass and occupies space

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BASIC MATTER can be broken down into

• ATOM
• SMALLEST PARTICLE THAT HAS PROPERTIES OF AN
  ELEMENT
• ELEMENT
• SUBSTANCE THAT CANNOT BE BROKEN DOWN INTO A
  SIMPLER SUBSTANCE
• 3. COMPOUND
• SUBSTANCE MADE OF ATOMS OF MORE THAN 1
  ELEMENT BOUND TOGETHER

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HOW ARE ELEMENTS AND COMPOUNDS WRITTEN?

• USING A FORMULA
• this representation uses chemical symbols and
  numbers that tell the number of atoms contained
  in the basic unit of the substance
• element N
• compound H2O

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What is the smallest unit of a substance that
exhibits all of the properties characteristic of
that substance?

• Molecule

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Examples of formulas

• C16H10N2O2 indigo
• 16 1022 30 atoms
• C8H10N4O2 caffeine
• 81042 24 atoms
• C3H8O rubbing alcohol
• 3 81 12 atoms

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What is the difference between a pure substance
and a mixture?

• Pure
• matter with a fixed composition and definite
  properties, cant be separated or broken down
  by physical actions such as boiling grinding or
  melting
• represented by a chemical formula
• C6H12 O6
• Mixture
• a combination of more than one pure substance
• air, grape juice

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Matter and EnergyWhat is the kinetic theory?

• All matter is made of atoms and molecules that
  act like tiny particles
• Tiny particles are always in motion
• the higher the temperature, the faster the
  particles move
• 3. At the same temperatures, the more massive
  particles move slower than the less massive
  particles

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What are the common states of matter?

• Solid
• fixed position, rigid, can vibrate, closely
  packed
• 2. liquid
• closely packed but can slide past each other
• gas
• constant state of motion, rarely stick
  together
• 4. plasma
• fast moving charged particles

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Solid fixed position, rigid, can vibrate,
closely packed 2. liquid closely packed but
can slide past each other gas constant
state of motion, rarely stick together 4.
plasma fast moving charged particles
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What is energy?

• Ability to change or move matter
• What does changing states of matter do to a
  substance?
• changes attractive forces between molecules,
  doesnt change composition of a substance

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State the law of conservation of mass?

• Mass can not be created or destroyed
• State the law of conservation of energy?
• Energy can not be created or destroyed.

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Changes of states of matter
sublimation
LIQUID
Boiling or evaporation
GAS
Solid
melting
condensation
freezing
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What is a chemical property of a substance?

• The way a substance reacts with others to form
  new substances with different properties by
  either combining with other elements or by
  breaking apart into new substances
• (corrosive, reactive,flammable)
• ex? mercurytoxic
• steel reactive with oxyen to
  form rust
• sodium . Flammable in O2

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What is reactivity?

• Ability of a substance to combine chemically with
  another
• What is flammability?
• Chemical property that describes whether
  substances will react in the presence of O2 and
  burn when exposed to flame

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What are physical properties?

• Characteristics of a substance that can be
  observed or measured without changing the
  composition of the substance
• Remain constant for specific pure substances
• Shape, color, odor, texture, melting point,
  boiling point, strength, hardness, ability to
  conduct electricity or heat, magnetism, density
• Ex? mercury is liquid at room temperature

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How to classify mixtures?

• By how thoroughly the substances mix together.
• Mix solid liquid.
• Homogeneous
• mixture clear and mixing occurs between
  the individual units and is the same throughout
• salt water salt water
• Heterogeneous
• cloudy mixture and mixture between
  substances isnt uniformly mixed
• flour water

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Liquid liquid

• Miscible
• Describes two or more liquids that are able to
  dissolve into each other in various proportions
• gasoline
• Immiscible
• Describes two or more liquid that do not mix into
  each other.
• oil and water

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DENSITY physical property

• D m/V density equals mass divided volume
• Buoyancy the force with which a more dense fluid
  pushes a less dense substance upward

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What is a chemical change?

• A change that happens when a substance changes
  composition by forming one or more new substances
• cellular respiration
• photosynthesis
• combustion
• clues energy released, smell or smoke

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What is a physical change?

• A change in the physical form or properties of a
  substance that occurs without a change in
  composition
• Ex melting, freezing, evaporating, grinding,
  dissolving,

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Inquiry lab pg 57 physical science
Volume of H2O Mass of cylinder H 2O Mass of H2O
0
10
20
30
40
50
60
70
80
90
100
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What is electron affinity?

• The attraction of an atom for an additional
  electron
• Metals have low affinity because they give away
  electrons
• Nonmetals have high affinity because they take on
  electrons
• The electron affinity tends to increase from left
  to right in the periodic table and from bottom to
  top

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What are families/groups?

• Elements grouped together by common properties.
  They fall in the same vertical column of the
  periodic table
• Column 1alkali metals (1 oxidation )
• Column 2 alkaline earth metals(2 oxid )
• Column 3-12 transition metals (many have
  multiple oxidation number-least reactive of the
  metals)
• Column 16 chalcogens (-2 oxidation )
• Column 17 halogens (-1 oxidation ) most
  reactive nonmetals
• Column 18 noble gases (0 oxidation )
  nonreactive due to filled outer energy level
• lanthanide series
• actinide series

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Where is the period in the periodic table?

• Horizontal rows in the periodic table
• Each represents an energy level

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What are metals?

• Groups of elements that has
• Luster (shiny)
• Good conductors of heat and electricity
• 1-3 valence electrons
• Located in the periodic table left of the
  metalloids excluding H
• Solids are room temperature(ex mercury)