# Chem 1H semes. 1 cards

## Terms

undefined, object
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base unit
defined unit in a systemof measurement/based on an object or event in physical world
-independent of other units
SI Base Units: name them for each of the following:
time
length
mass
temperature
amt. of a substance
electric current
luminous intesity
-TIME: second (frequency of microwae radation given by cesium-133 atom)
-LENGTH:meter(distance light travels through a vacuum in 1/299729458 seconds)
-MASS:kilogram(defined by platinum-iridium metal cylinder)
-TEMPERATURE: kelvin
-AMT OF SUBSTANCE: mole (mol)
-ELECTRIC CURRENT: ampere (A)
-LUMINOUS INTENSITY: candela (cd)
ratio for density
g/cm^3

density=mass/volume
Giga-scientific notation and symbol
10^9, G
mega
10^6, M
kilo
10^3, k
deci
10^-1, d
centi
10^-2, c
milli
10^-3, m
micro
10^-6, u
nano
10^-9, n
pico
10^-12, p
derived unit
a unit that is defined by a combination of base units
write the scientific notation for 428900000
4.289 x 10^8
multiplying scientific notations: multiply (2x10^3)(3x10^2)
multiply numbers 2x3=6
->6x10^5
dividing scientific notations: divide (9x10^8)/(3x10^-4)
divide numbers:9/3=3
->3x10^12
conversion factor
ratio of equivalent values used to express the same quantity in different units
-always equal to one
dimensional analysis
method of problem-solving that focuses on the units used to describe matter.
-ex: if you want to convert temp in *C to Kelvins, focus on the relationship between the units in the two temp scales
Accuracy
how close a measured value is to an accepted value
precision
how close a series of measurements are to another
equation for percent error
%error=(
error/accepted value)x100
significant figures
includes all the known digits plus ONE estimated one.
-72.3=3 sig figs
-60.5=3 sig figs
-6.20=3 sig figs
-0.0253=3 sig figs
-4230=3 sig figs
-counting numbers/defined constants have infinite number sig figs.
substance
matter that has a uniform and unchanging composition
-aka pure substance
-ex: table salt/water
physical property
a characteristic that can be observed without changing the sample's composition
-ex: density, c olor, odor, taste, hardness, melting point, boiling point
extensive property
-a physical property
-dependent upon amount of substance present
-length and volume are examples
intensive property
-physical property
-independent of amount of substance present
-ex: desntiy is the same no matter how much there is
chemical property
ability of a substance to combine with or change into one or more other substances
-ex: ability of iron to form rust when combined with air
states of matter: name the three big ones
-all matter that exists on earth is either a solid, liquid, or gas
physical changes
changing a substance without altering its composition
chemical change
aka "chemical reaction"
-changing a substance or substances into new substances
law of conservation of mass
mass is neither created or destroyed during a chemical reaction-it is conserved.
Mass (reactants)=mass(products)
mixture
combination of two or more substances
-each substance retains its individual chemical properties
name the types of mixtures
heterogenous
homogenous
solution
heterogenous mixture
a mixture that does not blend smoothly throughout adn which the individual substances remain distinct
-ex: sand/water mixture
ex: fresh squeezed orange juice (juice and pulp)
-ex: pizza w/ pepperoni and cheese
homogenous mixture
-constant composition throughout
-aka "solutions"
alloy
solid-to solid solution (homogenous mixture of metals, or mixture of metal and nonmetal)
name the four techniques to seperate mixtures
filtration
distillation
cyrstallization
chromatography
filtration
technique that used a porous barrier to seperate a solid from a liquid
ex: a cone in which the solid/liquid mixture is poured into and the liquid seeps through but the solid does not
Distillation
seperation technique for mixtures based on differences in teh boiling points of the substances involved
-a mixture is heated unti lteh substance w/ the lowest boiling point boils to a vapor that is then condensed to a liquid and collected
crystallization
seperation technique for mixtures that results in teh formation of pure solid particles of a substance from a solution containg the dissolved substnace. eventually crystals form
chromatography
seperates the components of amixture on the bases of teh tendancy of each to travel or be drawn across the surface of another material.
element
pure substance that cannot be seperated into simpler substances by physical or chemical means
-91 occur naturally
periodic table: name for the horizontal rows/name for the vertical columns
rows: periods
columns: groups or families
-elements in same group have similar chemical/physical properties
COMPOUND
combination of two or more different elements that are combined chemically
law of definite proportions
regardless of the amount, a compound is always composed of teh same elements in the same proportion by mass .

% by mass=mass of element/mass of compound x100
law of multiple proportions
when different compounds are formed by a co mbination of the same elements, different masses of one element combine with teh same relative mass of the other element in a ratio of small whole numbers
-ex: water, H:O> 2:1
Dalton's atomic theory:
-atoms
-all atoms of one element are exactly identical in every way
-atoms can't be mad, divided, or destroyed
-diff. atoms combine in simple whole number ratios to make compounds
-in chemical reaction: atoms are seperated, combined, rearranged
who was the first person to propose the idea that matter was not infinitely divisible? -first proposed the idea of "atomos"
Democritus
atom
smallest particle of an element that retains the properties of the element
electrons/what tool was used to discover these electrons?
negatively charge dparticles that are part of all forms of matter
-cathode ray tube
Robert Millikan
-first determined teh mass of an electron
proton
subatomic particle carrying a charge equal to but opposite of that of an electron
-positive charge of 1+
neutron
mass nearly equal to that of a proton's...but it carries no electrical charge
atomic number
number of protons in an atom
atomic#=#protons=#electrons
isotopes
atoms with the same number of protons but different number of neutrons
mass number
sum of the number of protons and neutrons in the nucleus.
ex: potassium isotope w/ 19 protons and 20 neutrons has mass number of 39.
-Ex: potassium isotope w/ 19 protons and 22 neutrons=41 mass number
atomic mass
the weighteed average mass of the isotopes of that element.
#45
is D
..according to natalie :)
haha
mole
SI base unit used to measure amount of a substance
-one mole of anything contains 6.022 x 10^23 representative particles
6.022 x 10^23
molar mass
mass in grams of one mole of any pure substance
-molar mass of any element is numerically equal to its atomic mass an dhas the units g/mol
chugga-chugga-choo choo
..you need a break every once in a while
ESTUDIA, NINA, ESTUDIA!!
tu vas a estar muy inteligente ya tu continuar a estudiar chemistry. pero tu vas a estar un gato feo y gordo ya tu te casas TRENTO SMITHO. pero ya tu te casas JAMES FRANCO, yo voy a estar te BRIDESMAID

alright. thats enough. i need to keep chugga-chugga-in my brain

now you see what happens when i get bored. the end.

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