1: Lab Skills, Physical Behavior of Matter and Energy Flashcards
What is the rule for adding/subtracting sig figs?
keep the least number of places after the DECIMAL POINT (it is NOT the least # of sig figs).
Rule for mult. and division of sig figs
round to the least number of sig figs.
Accuracy:
how close the experimental values are to the accepted/theoretical values.
Precision:
how close the experimental values are to one another.
graphing: x-axis
the independent variable
graphing: y-axis
dependent variable
graphing: title:
dependent variable versus independent variable (y vs. x)
Graphing: best fit curve or line:
general trend line, does not need to hit all points.
Graphing: extrapolation:
extend the line for unknown data WITH A DOTTED LINE
direct relationships are…
linear
inverse relationships are…
exponential
systematic error
when multiple trial results are clustered/precise, but accurate.
random error
when the values are neither precise nor accurate
density formula + table letter
d = m/v, table T
define Chemistry
the study of the structure, properties, and composition of substances and the changes that these substances undergo.
define matter
anything that has mass and volume (ie. takes up space)
what are the two types of properties of matter?
extensive and intensive
extensive properties
depends on amount of substance
ex: volume, mass
intensive properties
does not depend on amount of substance
ex: boiling point, color, density.
elements are..
the simplest form of matter
properties of elements:
- cannot be decomposed chemically
- homogenous
- all atoms of the same element have the same atomic number
diatomic elements (def.))
two elements of the same type bonded together.
define compounds
- they can be decomposed further by chemical change
- all samples of the same compound are homogenous
- Law of Definite Composition: all samples of the same compound have the same composition i.e. proportion of elements.
a chemical formula is both…
quantitative and qualitative
binary compound
a compound consisting of two different elements.
Matter is classified as… (two things)
a pure substance or a mixture of substances
Name the 7 diatomic elements:
H O F Br I N Cl (‘s)
name a monatomic element
neon
def shape, def. volume: solid
yes and yes
def. shape, def. volume: liquid
no and yes
def. shape, def. volume: gas
no and no
Properties of a solid (4)
- have a crystal lattice structure.
- molecules are close together and vibrate in place
- molecules DO NOT move from place to place
- solids are NOT COMPRESSABLE
are solids compressable?
no
crystal lattice structure
a regular geometric pattern in the arrangement of molecules.
“molecule” is used only to describe…
chemical formulas made up of all non-metals
Properties of liquids (5)
- molecules move around/are fluid
- molecules are farther apart than in solids
- liquids take the shape of container/indefinite shape
- not compressible
- definite volume
are the forces of attraction between liquid molecules stronger or weaker than in solids? in gases?
weaker. The forces of attraction between gas molecules are the weakest.
Properties of Gases(4)
- Molecules fill their container
- Molecules are very far apart
- Molecules move in straight line until they hit something
- indefinite shape and volume
salt
any positive ion bonded with a negative ion EXCEPT FOR HYDROGEN, which would create an acid (HCl)
