Chem 1H semes. 1 cards
Terms
undefined, object
copy deck
- 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
add exponents: 3+2=5
->6x10^5 - dividing scientific notations: divide (9x10^8)/(3x10^-4)
-
divide numbers:9/3=3
add subtract exponents: 8- -4=12
->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"
-ex: lemonade - 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 - avogadro's number
- 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.