General Chemistry 1 Week One Class NotesIf you want to learn more check out How much should a film earn for it to be considered as a blockbuster?
CHEMISTRY AND MEASUREMENTWe also discuss several other topics like Explain the mechanics of rigid bodies.
We also discuss several other topics like what is an unstated premise
Experiment -an observation carried out in a controlled manner so it can be duplicated If you want to learn more check out How many human genes are there, and what percent of these do all human share in common?
and conclusions can be made.If you want to learn more check out How to define functions?
iaw -a concise statement or education about a fundamental occurrence in nature.
Hypothesis -a tentative explanation of some regularity of nature.
Theory -a tested explanation of basic natural phenomenaWe also discuss several other topics like What makes peace complex?
•if a hypothesis passes many tests it becomes a hypothesis
-these are made from laws.
•experiments and explanations drive scientific advancement
SCIENTIFIC METHOD STEPS
Matter -whatever occupies a space and can be perceived by our senses.
Mass - the quantity of matter in a material.
Law of conservation of mass -created by Antcine Lavoiser; mass remains constant
During a chemical reaction (the mass before the reaction = the mass after).
Lavoisier applied his law to burning. He noticed that burning mercury dreated
mercury ( 11) oxide in equal proportion
Mercury + oxygen → mercury (11) oxide
MASS VSS. WEIGHT
Weight is proportional to the force of gravity exerted on it, it changes in different
gravities (such as the moon) but mass never changes because it is the amount of
Matter something has.
Known for being
An incompressible fluid
An compressible fluid
PHYSICAL + CHEMICAL CHANGES
Physical change -a change in state (liquid to solid)
Chemical change -any change that produces new substances (mercury + oxygen →
Mercury (ll) oxide).
PHYSICAL + CHEMICAL PROPERTY
Physical Property -a characteristic that can be observed without changing its chemical
identity (color, melting point, etc.)
Chemical Property -a characteristic involving a chemical change (Fe can react with O2
To make rust).
Substance -matter that cannot be separated by a physical process.
Element -a substance that cannot be decomposed by any chemical reaction.
Compound -2 or more elements that are chemically combined
>Law of definite proportions (A.K.A. Law of constant composition) -compounds
Have consistent elemental proportions (there will always be 2 hydrogen and
1 oxygen in water).
Mixture -elements that can be physically separated
>heterogeneous mixture -has physically different parts with different properties
(stirring salt and sugar together).
>homogeneous mixture -(A.K.A. a solution) -has uniform properties (sodium
chloride mixed with H2O until it dissolves.
Phase -the physical state (solid, liquid, gas)
Precision -closeness to previous data.
Accuracy -closeness of a measurement to an actual value
Sig Fig Rules
9.12 .912 .00912 all have 3 Sig Figs
All have 3 Sig Figs: 9.00 cm, 9.10 cm, 90.0 cm
To avoid confusion.
✱exact numbers have infinite Sig Figs.
3.0g x 9 coins = 27g
↑ ↑ ↑
3sg ∞sg 3sg
S1 Base Units -units of measurement from the international system of units from which all
Other units can be derived.
S1 BASE UNIT CHART
S1 prefix -a prefix used to indicate a power of 10.
✱a common non-s1 unit is the angstrom (Å), which equals 10-10 m.