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level: Terms

Questions and Answers List

level questions: Terms

QuestionAnswer
determines the quantity, dimensions, or extent of somethingmeasurement
a definite quantity adapted to as a standard of measurementunit
how close the measurement is to the "true" valueAccuracy
the degree to which the measurement is reproducablePrecision
a digit that is either reliably known or estimatedSignificant digit
how many sig figs are in 1.233
how many sig figs are in 0.00122
how many sig figs are in 0.11004
how many sig figs are in 25002
how many sig figs are in 0.090304
how many sig figs are in 109.04
how many sig figs are in 0.009003
round this to 3 sig figs: 53455350
round this to 3 sig figs: 0.014570.0146
round this to 3 sig figs: 1.0531.05
the comparison of the experimental measurement to its accepted value.percent error
cannot be described in terms of anything else. ex: mass=kg, length=m, time=sFundamental measurement unit
fundamental measurements combined to make a derived unit. ex: speed=m/s, density=g/cm^3Derived measurement unit
the study of matter and the changes it undergoeschemistry
anything that has mass and occupies spacematter
the most basic form of matter (ex: silver, gold, copper)element
composed of small indivisible particles called atomsmatter
composed of atoms and different elements combined in small whole-number ratioschemical compounds
the rearrangement of atoms into different combinationschemical reactions
smallest fundamental particle of an element that has the properties of that elementatom
the first particle discovered (JJ thompson 1897)electron
electrons have a _______ chargenegative
+ in the nucleusprotons
0 in the nucleusneutrons
- outside the nucleuselectrons
number of protons in the nucleusatomic
protons + neutronsmass number
atoms of the same element with differeing mass numbersisotopes
substance composed of two or more elements that are chemically combined (water, table salt, sugar)Compound
made up of atomsElements
a substance where the atoms are held together by covalent bonds, ex: H2Omolecular compounds
compounds consisting of ions (atoms who have gained either a positive or negative charge)Ionic compounds
electrostatic forces holding the ions togetherIonic bonds
charged particleIon
positive charged particleCation
negative charged particleanion
matter is neither created nor destroyed in chemical reactionslaw of the conservation of mass
solids, liquids, gasphysical states
have definite composition and definite unchanging propertiespure substances
pure substances tendency to undergo chemical change. ex: burning, color changes, tarnishingchemical properties
a substance exists in a particular physical state under defined conditions. increase in temp will alter physical state (ex: color, odor, taste)physical properties
property that does not depend on the amount of material (ex: density)intensive properties
property that does depend on the amount of material present (ex: mass, volume)extensive property
when a substance is chemically converted to another substance.chemical change
ratio of mass to volume - an intensive propertydensity
change in physical property (ex: melting, freezing)physical change
non-uniform mixture containing two or more substances (ex: salt and pepper, oil and water)heterogeneous mixture
uniform mixture, same throughout (ex: salt water, milk)Homogeneous mixture
substance being dissolvedsolute
substance doing dissolvingsolvent
the capacity to do workenergy
energy cannot be created nor destroyed, but only transformed from one form to anotherlaw of the conservation of energy
produce energyexothermic reactions
require energyendothermic reactions
energy availalbe due to position or compositionpotential energy
energy resulting from motionkinetic energy
amount of heat required to raise the temp of one gram of water from 14.5C to 15.5Ccalorie (cal)
the amount of heat required to raise the temperature of one gram of a substance to one degree celsius (kelvin) - reflects how some substances heat up faster than othersspecific heat