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Chemistry 1.1- 1.3 quiz

Terms in this set (24)

matter
is composed of various types of atoms
one substance changes to another
by reorganizing the way the atoms are attached to each other
Scientists try to understand nature and the changes that occur in nature
by applying a process called the scientific method
scientific method
1. making an observation (collecting data)
2. suggesting a possible explanation for the observation (formulating a hypothesis)
3. Doing experiments to test the hypothesis
an observation that is made while carrying out the scientific method may be either:
Qualitative, which does not involve a number (the sky is blue; water is a liquid)

Quantitative, which involves a number as well as a unit (water boils at 100C; a certain book weighs 2 kg) A quantitative observation is called a measurment
When an experiment is carried out to test a hypothesis
new observation(s) will be made
if these observations support the hypothesis
then the hypothesis will be considered valid
if these observations do not support the hypothesis
then the hypothesis will be considered invalid
Whether or not experimental observations have found a hypothesis to be valid
these observations are new and thus can be explained by yet another hypothesis that can be tested, repeating the scientific method all over again
After the scientific method has been repeated enough times to generate a set of hypotheses that are valid
this set of hypotheses is used to help give scientist an overall explanation or interpretation of why something in nature behaves in a particular way
this this interpretation is known as a
theory or a model
Theories can and will change as scientist preform more and more experiments
it is necessary to continue to refine our theories if we hope to approach a more complete understanding of nature
an observation made while carrying out the scientific method
may sometimes found to be a behavior that is generally observed across many different systems
when a certain behavior is consistently observed across various systems
it can be called a natural law
most scientist use units from the
International system
There are 7 units in the Si system defined as the
fundamental SI units
fundamental SI units
Mass: kilogram: kg
Length: meter: m
Time: second: s
Temperature: kelvin: K
Electric current: ampere: A
Amount of substance: mole: mol
Luminous intensity: candela: cd
derived Si units
speed/ velocity: meters per second: m/s
volume: meters cubed: m3
area: meters squared: m2
some derived Si units have special names and symbols that are interchangeable with the original unit name and symbol
(physical quantity: electric charge Unit name:seconds times amperes symbol: S A) special unit name: coulomb special symbol: C
unit prefixes
can be placed in front of an Si unit to change the size of it to a more convenient one
unit prefixes symbols
prefix: mega, Symbol: M, Meaning: 1,000,000 , notation: 10to6

kilo: k: 1,000: 10 to 3

hector: h: 100: 10 to 2

deka: da: 10: 10

deci: d: 0.1: 10 to -1

centi: c: 0.01: 10 to -2

milli: m: 0.001: 10 to -3

micro: μ: 0.000001: 10 to -6

nano: n: 0.000000001: 10 to -9
when an Si unit (whether derived or fundamental) contains a prefix
it is still considered an Si unit
mass
is a measure if the resistance of an object to a change in its state of motion and depends on the amount of matter in an object
weight
is the amount of gravitational force being exerted on the object; since the strength of the gravitational field can vary
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