Exam Thorough Review, Complete Solution
Accuracy
how close a measurement is to the true value
dependent variable
changes in response to the independent variable (what you measure in an experiment
and what's affected during the experiment)
Hypothesis
a proposed explanation for an observation
Independent variable
(often denoted by x) doesn't depend on something else
Scientific notation
how scientists handle large or small numbers
Significant Figure
all the nonzero digits of a number and the zeros that are included between them or that
are final zeros and signify accuracy
SL unit for mass
based on meter, kilogram, second, ampere, kelvin, and mole w/ set of prefixes to
indicate multiplication or division by a power of ten
Theory
well-supported explanation that's been repeatedly tested
Aristotle
laid the foundation for science (constructed an explanation for his observations of falling
objects)(only made logical assumptions from observations)
Galileo
tested his theories
(T/F) Science cannot prove anything 100%
(true) science cannot prove anything 100%
Science
Process that follows rules/procedures to answer questions about the natural world
How many new experiments does it take to disprove a theory?
It takes one new experiment to disprove a theory
The scientific method is an ___ process
The scientific method is an ONGOING (or fluid) process
Scientific Method Steps
Observe, hypothesis, test hypothesis, make conclusion, report result
precision
How close two measurements are to each other
Write 7.7847 * 10^4 in standard notation w/ 2 sig figs
78,000
Write 7.4 * 10^-2 in standard notation w/ 2 sig figs
0.074
Physical properties
associated w/ characteristics of molecules that can be tested w/out changing the
chemical make-up of compounds (magnetism, boiling point, melting point, color, taste)
, (T/F) Decomposition is considered a physical change
False, decomposition is a chemical change because molecules are changing
Chemical change
Chemical reaction, chemical makeup is changed
Physical change
When a substance's physical form is changed
What is the difference between a property of matter and a change in matter?
Properties tell us about elements, and changes determine these properties
(physical/chemical) Cutting paper
Physical
(physical/chemical) boiling vinegar
Physical
(physical/chemical) Iron nail rusting
Chemical
(physical/chemical) Reacting magnesium with hydrochloric acid
Chemical
Four states of matter
Solid (snow), liquid (water), gas (helium), plasma (lightning strikes)
3 Criteria of classifying matter
Compressibility, shape, volume
Shape and volume are defined in terms of ___ or ___
Definite (can't be changed) or Indefinite (can be changed)
(T/F) Liquids are compressible
False, liquids are not compressible
(T/F) Gases have higher compressibility than liquids
True, gases have higher compressibility than liquids
What state of matter has an indefinite shape and is compressible?
Liquids
Which state of matter is compressible and has indefinite shape?
Gases
(T/F) Liquids have indefinite shapes, but are still incompressible
True, liquids have indefinite shapes but are incompressible
Solids have ___ volume
definite
Solids have a ___ volume, ___ shape, and are ___.
Solids have a DEFINITE volume, DEFINITE shape, and are INCOMPRESSIBLE
extensive property
depends on the amount of matter in a sample (ex? mass and volume)
intensive property
does not depend on the amount of matter in a sample (ex? boiling point, freezing point,
temp, color, hardness, density of water. 1 cup has the same density of 1 gallon)
(intensive/extensive) Melting Point
Intensive
(intensive/extensive) Length
Extensive
(intensive/extensive) width