chemistry lesson 1-4 Flashcards
anything that has mass and takes up space
matter
is the study of matter and the changes that it undergoes.
chemistry
is the use of evidence to construct testable explanations and predictions. Science is also the knowledge gained from this process.
science
Branches of chemistry:
-organic chemistry
-inorganic chemistry
-physical chemistry
-analytical chemistry
-biochemistry
-environmental chemistry
a testable explanation of a situation or phenomena is called a
hypothesis
an explanation that has been repeatedly supported by many experiments.
theory
a ____states a broad principle of nature that has been supported over time by repeated testing (how and why)
theory: evolution, relativity, bbt
is a relationship in nature that is supported by many experiments, and no exceptions to these relationships are found. (what)
scientific law
is research to gain knowledge for the sake of knowledge itself.
pure reasearch
, the study of carbon molecules in space led to the discovery of buckminsterfullerenes.
pure research
research undertaken to solve a specific problem.
applied research
scientists have developed ways to use buckminsterfullerenes to fight cancer.
applied research
a measurement that reflects the amount of matter,
mass
a measurement of Earth’s gravitational pull on matter.
weight
also called a chemical, is matter that has a definite and uniform composition.
substance
-chemistry uses ______ of matter at the submicroscopic or atomic scale to explain the behavior of matter at the macroscopic scale.
models
visual representation of something that helps you better understand something. better explain a concept
model
Which of these is another word for substance?
chemical
a measurement that reflects the amount of matter an object contains
mass
is a defined unit in a system of measurement that is based on an object or event in the physical world.
base unit
base units:
time, length, mass temperature, amount of substance
time-
seconds (s)
length
meter(m)
mass
kilogram (kg)
temperature
kelvin (K)
amount of substance
mole (mol)
-A unit that is defined by a combination of base units is called a
derived unit
The SI unit for speed is meters per second (m/s) is an example of what?
derived unit
derived unit examples:
velocity, acceleration, volume, density
-A more common unit of volume is the ______, which equals 1 cubic decimeter (dm3).
Liter
a physical property of matter defined as the amount of mass per unit volume.
density
equation for density:
density= mass/ volume
can be used to express any number as a number between 1 and 10 (the coefficient) multiplied by 10 raised to a power (the exponent).
scientific notation
is a systematic approach to problem solving that uses conversion factors to move or convert, from one unit to another.
dimensional analysis
is a ratio of equivalent values having different units.
conversion factor
refers to how close a measured value is to an accepted value.
accuracy
refers to how close a series of measurements are to one another. (group of things)
precision
is defined as the difference between an experimental value and an accepted value.
error
error equation:
error=experimental value-accepted value
expresses error as a percentage of the accepted value
percent error
percent error equation:
percent error= error/accepted value x 100
The precision of a measurement is indicated by the number of digits reported. The reported digits are called
significant figures
a visual display of data that makes trends easier to see than in a table.
graph
examples of graphs:
circle, line, bar
the variable deliberately changed in an experiment- is plotted on the x-axis.
independent variable
physically control and manipulate
independent variable
the value of which changes in response to the independent variable- is plotted on the y-axis.
dependent variable
