Observation What is evidence Any observation of Natural

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Observation - What is evidence? • Any observation of Natural Phenomena – Qualitative •

Observation - What is evidence? • Any observation of Natural Phenomena – Qualitative • Use your senses • Ex. Texture, color, smell, taste, sound – Quantitative • Measured values • Ex. Weight, volume, length, temperature • Measurements, Verifiable observations, etc. • Utilizing the Scientific Method, this is how we know what we know!

Organization of Matter • Continuous – Aristotle • Discontinuous – Democritus • (470 -400

Organization of Matter • Continuous – Aristotle • Discontinuous – Democritus • (470 -400 B. C. ) – Dalton • (1808) – Joseph Gay-Lussac • (1805)

States of Matter Solid: high degree of interparticle forces Liquid: significant degree of interparticle

States of Matter Solid: high degree of interparticle forces Liquid: significant degree of interparticle forces Gases: very low degree of interparticle forces Water can be found in the solid, liquid, and vapor (gaseous) forms simultaneously.

Changes of Matter Physical: a change which does NOT alter the composition of a

Changes of Matter Physical: a change which does NOT alter the composition of a substance. i. e. : cutting, breaking, tearing, phase changes (melting, boiling), etc. Chemical: a change which alters the composition of a substance. i. e. : “rusting”, burning, “chemically reacting”, etc. The green color of the Statue of Liberty results from the reaction of copper with the components of air.

"Good" versus "Bad" Properties for a Chemical Substance

"Good" versus "Bad" Properties for a Chemical Substance

Properties & Changes of Matter

Properties & Changes of Matter

Organization of Matter

Organization of Matter

How could the appearance of each type of chemical change? Outward physical appearance of

How could the appearance of each type of chemical change? Outward physical appearance of naturally occurring elements Hg As S Bi Mg I 2

Laws of Matter • Law of Conservation of Mass – Amount of matter does

Laws of Matter • Law of Conservation of Mass – Amount of matter does not change during a physical or chemical reaction • Law of Definite Proportions – In samples of a chemical compound, the masses of the elements are always in the same ratio • Ex. H 2 O • Law of Multiple Proportions – Two or more elements may form more than one compound. • Ex. H 2 O and H 2 O 2

Studying Matter - Chemistry • Requires a scientific approach – Scientific method – Nature

Studying Matter - Chemistry • Requires a scientific approach – Scientific method – Nature of science • Requires use of a measurement system and tools for measuring • Requires displaying and explaining experimental results – Variables (dependent vs. independent) & controls

Metric System • Be able to measure/calculate mass, volume, distance, density & temperature

Metric System • Be able to measure/calculate mass, volume, distance, density & temperature

Measuring Length § The scale on a measuring device determines the magnitude of the

Measuring Length § The scale on a measuring device determines the magnitude of the uncertainty for the recorded measurement. • Include all certain digits plus one uncertain digit in your measurement! – significant (figures) digits (sd)

Volume/Space • Liter • Milliliter • Microliter (L) (m. L) ( L) 1 L

Volume/Space • Liter • Milliliter • Microliter (L) (m. L) ( L) 1 L = 1 dm 3 1 m. L = 1 cm 3 = 1 cc 1 L = 1 mm 3

Measuring Volume • Note the type of liquid • Indicate which kind of meniscus

Measuring Volume • Note the type of liquid • Indicate which kind of meniscus it is (concave or convex) – Concave: read the bottom of the meniscus (WATER) – Convex: read the top of the meniscus (MERCURY) • Include all certain digits plus one uncertain digit in your measurement! – sd

Mass/Weight • A gram is defined as the mass of 1 ml of water

Mass/Weight • A gram is defined as the mass of 1 ml of water at 4�˚C. Therefore, water has a density of 1 g/m. L at 4˚ C.

Measuring Mass • Check that the scale is TARED prior to placing anything on

Measuring Mass • Check that the scale is TARED prior to placing anything on it. • Include all certain digits plus one uncertain digit in your measurement! – sd

Converting between Measurement Units

Converting between Measurement Units

Conversions 453. 6 graham crackers = 1 pound cake 2000 mockingbirds = 2 kilomockingbirds

Conversions 453. 6 graham crackers = 1 pound cake 2000 mockingbirds = 2 kilomockingbirds

Distance Conversion It is experimentally determined that 1 inch equals 2. 54 cm, or

Distance Conversion It is experimentally determined that 1 inch equals 2. 54 cm, or 1 cm equals 0. 394 inch