How can we help?

You can also find more resources in our Help Center.

61 terms

Chemistry Unit one

STUDY
PLAY
physical change
alters only state or appearance; not composition (subliming or dissolving)
Chemical change
a change that occurs when a substance changes composition by forming one or more new substances (rusting, changing color, burning)
physical properties
characteristics displayed without changing composition
chemical properties
characteristics displayed only by changing composition via chemical change
kinetic energy
energy due to motion, including thermal energy
thermal energy
energy due to temperature
potential energy
energy due to position or composition
work
action of force through distance
energy
capacity to do work; can be converted from one form to another
law of conservation of mass
energy is neither created nor destroyed
What are the properties of matter determined by?
the atoms and molecules that compose it
atoms
submicroscopic particles; fundamental building blocks of ordinary matter
molecules
2 or more atoms attached together in a specific geometrical arrangement; come in different shapes and patterns and are made up of atoms
chemistry
science that seeks to understand behavior of matter by studying behavior of atoms and molecules
liquids
particles closely packed, but have some ability to move around; fixed volume but not shape, incompressible, able to flow
amorphous solids
solids with particles randomly distributed without any long range pattern (plastic, glass, or charcoal)
crystalline solids
solids with particles arranged in patterns with long range repeating order (salt, diamonds, sugar)
solids
particles packed tightly together in fixed positions; can vibrate but not move, fixed shape and volume, do not flow and are not compressible
matter
substance that has and occupies volume and has mass; classified by it's state and composition
scientific theory
things in nature are the way they are and behave the way they do. explains WHY
scientific law
statement that summarizes all past observations and predicts future observations; describes what happens; can be tested by experiments
experiment
set of highly controlled procedures designed to test whether an idea about nature is valid; generates observations that either validate or invalidate hypothesis
hypothesis
tentative interpretation or explanation for observation; can be tested to be proven wrong
quantitative
observation that includes numbers
qualitative
observation of characteristics
gases
particles have a lot of room to move around each other; take on shape and volume of container; compressible
composition
types of particles, arrangement of particles, attractions and attachments between particles
pure substance
first component, composition doesn't change from one sample to another
mixture
2 or more components, composition may vary from one sample to another
elements
can not be chemically broken down into simpler substances
compounds
can be chemically broken down into simpler substances
homogenous mixture
uniform composition throughout; also called a solution (salt water)
heterogenous mixture
composition varies throughout (too much salt, some falls to the bottom, leaving uneven composition)
filtration
separation technique involving a funnel
distillation
bunson burner heats flask, sending gas down a tube while it cools into another flask
Mega
M, 1,000,000
Kilo
k, 1,000
deci
d, .1
centi
c, .01
milli
m, .001
micro
.000001
nano
n, .000000001
2.54
1in= ?cm
lbs to grams
1lb=453.59 grams
1.057
1 liter ? quarts
density formula
g/ml or g/cm^3
how do you round when measuring?
round one digit past the graduation mark
intensive properties
amount of substance (used to identify substances)
Extensive properties
amount of substance (cannot be used to identify substances)
density
ratio of mass to volume
significant figures
non placeholding digits
exact number
value known with complete certainty
accuracy
a description of how close a measurement is to the true value of the quantity measured
precision
how close a series of measurements are to one another
dimensional analysis
using units as a guide to solve problems (always include units in calculations)
conversion factor
fractional quantity with units converting from unit on bottom and converting to unit on top
random error
unpredictable error with no obvious pattern
systematic error
a repeated error which affects every measurement to the same degrees - caused by a technique problem or instruments.
1.093
How many km are in a mile?
Law of multiple proportions
WHEN 2 ELEMENTS (A+B) FORM 2 DIFFERENT COMPOUNDS, MASSES OF B THAT COMBINE WITH 1g OF A CAN BE EXPRESSED AS A RATIO OF SMALL WHOLE NUMBERS.
Law of definite proportions
the law that states that a chemical compound always contains the same elements in exactly the same proportions by weight or mass