Flashcards
Chem 152
Cards in this deck (46)
- 1Scientific LawsSimple statements of natural phenomena to which no exceptions are known under the given conditions.
- 2TheoryA well established hypothesis
- 3HypothesisA uncertain explanation of certain facts that provides a basis for further experimentation.
- 4ObservationThe analysis that contributes with the laws and hypothesis
- 5SolidA solid has a definite shape and volume, with particles that cling rigidly to one another.
- 6LiquidHas a definite volume but not a definite shape, with particles that stick firmly but not rigidly.
- 7GasHas an indefinite volume and no fixed shape, with particles that move independently of one another.
- 8Pure Substance(element or compound) always has a definite composition by mass/ The elements in the compound lose their identities and may be separated only by chemical means
- 9MixtureAlways contains two or more substances that can be present in varying amounts/ the components of a mixture do not lose their identities and may be separated by physical mean.
- 10HomogeneousExactly the same appearance and properties
- 11HeterogeneousDifferent phases and involves 2 or more physical appearance
- 12MeasurementA quantitative observation
- 13Sig Fig (Multiplication & Division)The answer must contain the same number of sig fig as in the measurement that has the least number of sig figs.
- 14Sig Fig ( Adding and Subtracting)Answers must be expressed to the same precision as the least precise measurement.
- 15Metric SystemAlso known as International System(SI) is a decimal system of units for measurements of mass, length, time, and other physical quantities.
- 16Metric System Units1 kilometer= 1000 meters
1 kilogram= 1000 grams
1 millimeter= 0.001 meter
1 microsecond = 0.000001 second - 17Dimensional Analysis: A 1.50lb package contains how many grams of baking soda?1 lb= 453.6g
(1.50lb)(453.6g/lb)=680.g - 18Temperature Conversions
- 19Densitydensity=mass/volume
- 20ElementA fundamental or elementary substance that can not be broken down by chemical means to simpler substances.
- 21CompoundA distinct substance that contains two or more elements chemically combined in a definite proportion by mass.
- 22MetalSolids at room temperature (mercury is an exception).
- 23NonmetalsNot shiny, have a relatively low melting points and densities and are generally poor conductors of heat and electricity.
- 24MetalloidAn element having properties that are intermediate between those of metals and nonmetals(e.g., silicon); these elements are useful in electronics
- 25Chemical FormulaShows the symbols and the ratio of the atoms of the elements in a compounds. Ex: Sodium chloride contains one atom of sodium per atom of chlorine; its formula is NaCl
- 26MoleculeThe smallest uncharged individual unit of a compound formed by the union of two or more atoms.
- 27IonicA positively or negatively charged atom or group of atoms. Ionic compound is held together by attractive forces that exist between + and - charged ions.
- 28CationA positively charged ion
- 29AnionA negatively charged ion
- 30Chemical PropertyThe ability of a substance to form new substances either by reaction with other substances or by decomposition.
- 31Physical PropertiesAre the inherent characteristics of a substance that can be determined without altering its composition; they are associated with its physical existence.
- 32Chemical ChangeNew substances are formed that have different properties and composition from the original material.
- 33Physical ChangeAre changes in physical properties (such as size, shape, and density) or changes in the state of matter without an accompanying change in composition.
- 34Law of Conservation of mass and energyEnergy can be neither created nor destroyed, through it can be transferred from one form to another.
- 35Law of Conservation of massNo change is observed in the total mass of the substances involved in a chemical reaction; that is, the mass of the products equal the mass of the reactants.
- 36Potential Energy (PE)Is stored energy, or energy that an object possesses due to its relative position. Ex: a ball located 20ft above ground has more potential energy than when located 10ft above the ground and will bounce higher when allowed to fall.
- 37Kinetic Energy (KE)Energy that matter possesses due to its motion.
- 38q = m x c x Δt, q= -qq=heat
m= mass
Δt= specific heat
c= Δt - 39Joules4.184 joules = 1 cal, 1Cal = 1kcal
- 40Daltons Atomic ModelThe first modern atomic theory to state the elements are composed of minute individual particles called atoms.
- 41What is an ion, cation, anion and how are they formed
- 42e’electron is a particle with a negative electrical charge and a mass of 9.110x10^-28g
- 43pProton: a subatomic particle found in the nucleus of the atom that carries a positive electrical charge and a mass of about 1 amu. An H+ ion is a proton.
- 44nNeutron: A subatomic particle that is electronically neutral and is found in the nucleus of an atom.
- 45IsotopesAtoms of a given element having the same atomic number but different atomic masses.
- 46Atomic MassThe average relative mass of the isotopes of an element referred to the atomic mass of carbon-12