Chem Midyear

Front 1

quantity

Back 1

a quantity is something that has magnitude size or amount

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weight

Back 2

a measurement of the gravitational pull on matter

Front 3

derived si units

Back 3

combinations of si base units afrom derived si units

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volume

Back 4

the amount of space occupied by an object

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density

Back 5

the ratio of mass to volume

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conversion factor

Back 6

the ratio derived from the equality between two different units that can be used to convert from one unit to an other

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accuracy

Back 7

accuracy refers to the closeness of measurements to the correct or accepted value of the quantity measured

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precision

Back 8

precision refers to the closeness of a set of measurements of the same quantity

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percent error

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calculated by subtracting the accepted value from the experimental value and then dividing nthe difference by the accepted value and then multiplying by 100

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significant figures

Back 10

sig figs in a measurement consist of all the digits known w/ certainty plus one final digit which is somewhat uncertain or is an estimate

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Groups/familes

Back 11

the vertical columns of the periodic table

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periods

Back 12

the horizontal rows of elements in the periodic table

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metal

Back 13

a metal is an element that is a good conductor of heat and electricity

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nonmetal

Back 14

a nonmetal is an element that is a poor conductor of heat and electricity

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metaloid

Back 15

an element that has some characteristics of metals and some characteristics of non-metals

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thermo-chemistry

Back 16

the study of the transfers of energy as heat that accompany chemical reactions and physical changes

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calorimiter

Back 17

the tool that measures the energy absorbed or released as heat in a chemical or phys change

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temperature

Back 18

a measure of the average kinetic energy of the particles in ia sample of matter

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joule

Back 19

is the si unit for heat

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heat

Back 20

energy transferred between samples of matter because of a difference in their temperature

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specific heat

Back 21

the amount of energy required to raise the temp of one gram of a substance by 1 degree celcius

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heat of reaction

Back 22

the quantity of energy released or absorbed as heat during chemical reactions

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Atomici #

Back 23

the # of protons in the nucleus of each atom of that element

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isotopes

Back 24

atoms of the same element that have different masses

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Mass #

Back 25

the total # of protons and nutrons in the nucleus of an isotope

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nuclide

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a gneral term for any isotope of any element

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atomic mass unit

Back 27

1 amu is exactly 1/12 the mass of a carbon-12 atom

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average atomic mass

Back 28

the weighted average of the atomic masses of the naturally occuring isotopes of an element

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mole

Back 29

the amount of a substance that contains as many particles as there are atoms in 12 g of carbon 12

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avegardos #

Back 30

the # of particles in one mole of a pure substance

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mollar mass

Back 31

the mass of one mole of a pure substance

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law of conservation of mass

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states that mass is neither destroyed nor created during ordinary chem. reactions

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law of definite proportions

Back 33

the fact that a chemical compound contains the same elements in exactly the same proportions by mass regardless of the size of the sample or source of the compound

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law of multiple proportions

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if 2 or more different cmpds are composed fo the same 2 elmts then the ratio of masses of the 2nd elmt combined w/ a cetain mass of the 1st elmt is always a ratio of small whole #s

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Atom

Back 35

the smallest particle of an element that retains the chemical props of that element

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nuclear forces

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short-range proton-proton, proton-neutron,and neutron-neutron forces, they hold the nuclear particles together

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electromagnetic radiation

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a form of energy that exhibits wavelike behaviors as it travels through space

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electromagnetic spectrum

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all forms of electromagnetic radiation form the electromagnetic spectrum

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wavelength

Back 39

the difference between corresponding points on adjacent waves

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photo electric effect

Back 40

refers to the emission of electrons from a metal when light shines on the metal

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quantum

Back 41

the minimum quantity of energy that can be lost or gained by an atom

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photon

Back 42

particle of electromagnetic radiation having zero mass and carrying a quantum of energy

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ground state

Back 43

the lowest energy state of an atom

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excited state

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is a state in which an atom has a higher potential energy than it has in its ground state

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line-emission spectrum

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when a narrow beam of the emitted light was shined through a prism, it was separated into a series of specific frequencies of visible light

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contiunuous spectrum

Back 46

the emissions of a contiunous range of frequencies of electrom agnetic radiation