Exam Review

Define Chemistry
The study of the composition of matter and the changes that matter undergoes.
Steps of the scientific method
1. make and observation
2. test a hypothesis
3. develop theories
Define Substance
Matter that has uniform and definite composition.
(2) examples of substances
gold and copper
Define Physical Property
can be observed without changing composition
List (7) physical properties
color, density, mass, melting pt, volume, odor, malleability
List physical changes
cutting, grinding, bending, freezing, melting, dissolving
Define mixture and give an example of the 2 types of mixtures.
a physical blend of two or more substances; hetero: salad, homo: salt water.
List 2 ways of separating mixtures.
dissolving, distillation
List 2 ways of separating mixtures.
dissolving, disstillation
Define Compound
substance that can be separated into similar substances by chemical means
Define chemical change
a change that produces matter with a different composition of the original matter.
Define Chemical reaction
a change in which one or more reactants change into one or more products
Define chemical property
the ability of a substance to undergo a specific chemical change
What is the law of conservation of mass?
Mass of the reactants is equal to mass of the products.
Percent Error formula
theoretical minus actual over actual
What are the (4) tenets of Dalton’s atomic theory?
1. all elements are composed of atoms 2. atoms of the same element are identical 3. atoms of different elements can chemically combine 4. chemical reactions occur when atoms are joined, separated, or rearranged
What are the (3) subatomic particles? What are their masses, location, and charges?
Proton: 1, nucleus, +1
Neutron: 1, nucleus, 0
Electron: 1/1840, electron cloud, -1
What is the significance of Rutherford’s Gold Foil Experiment?
It told us that the nucleus is mostly empty space.
Define atomic number
number of protons in the nucleus of an atom
Define mass number
the total number of protons and neutrons in the nucleus
Define atomic mass
the weighted average of the masses of the isotopes of an element
What group are the alkali metals located?
In what group are the alkaline metals located?
In what groups are transition metals located?
Where are the inner transition metals?
the bottom two rows
In what group are the noble gases located?
Define radioisotopes
isotope with unstable nucleus that undergoes radioactive decay
Define radioactivity
process in which nuclei emit particles and rays
Define radioactive decay
unstable nuclei emits ionized particles and rays
What is the charge, penetrating power and shielding requirements for the (3) types of decay?
Alpha: +2, low, paper
Beta: -1, moderate, aluminum foil or wood
Gamma: 0, very high, concrete, lead
Define fusion and fission
Fusion: combining of nuclei
Fission: splitting of nuclei
What type of nuclear reaction is used in nuclear power plants?
What are properties of molecular compounds?
two non-metals, molecule, solid, liquid or gas at room temp, low melting point
What are properties of Ionic compounds?
metal and a non-metal, fu, solid at room temperature, high melting point
Define percent yield
ratio of actual yield and theoretical yield, a measure of the efficiency of the reaction.
Daltons model of the atom
tiny, indestructible, no internal structure
Thomson’s model of the atoms
plum pudding
Rutherford’s model of the atom
dense, positively charged nucleus which the electron move around
Bohr’s model of the atom
electrons move in circular orbits
Shrodinger’s model of the atom
electron cloud
Define quantum
amount of energy needed to move an electron from one orbit to another
Aufubau Principal
the lower energy levels fill first
Pauli Exclusion Principal
two electrons per orbital
Hund’s rule
each orbital will fill with 1 electron before they start to double up
How are energy and wavelength related?
How is frequency related to wavelength?
Planck’s constant
Which would be larger in atomic size? K or As?
Define electronegativity
tendency of an atom to attract electrons when combined with another element
Which is least electronegative? Rubidium or Oxygen?
Define ionization energy
energy required to remove an electron from a gaseous atom
Which element would have the greatest ionization energy? Cl or I?
In ionic bonding, electrons are _______
Define valence electrons
electrons in the highest energy level
In a covalent bond electrons are _______
Define VESPR theory
because electrons repel each other, the molecular shape adjusts so the valence e- pairs are as far apart as possible.
Define dispersion forces
created by motion of electrons. as number of electrons increases, dispersion forces increase
Define dipole interaction
when polar molecules are attracted to each other
Define hydrogen bonding
when a hydrogen covalently bonded to a very electronegative atom is also weakly bonded to an unshared e- pair of another electronegative atom
Define kinetic energy
energy an object has because of its motion
SI unit of pressure
Increased kinetic energy cause _______ in temp
Boiling point is when…
vapor pressure= external pressure
Differentiate between a real gas and an ideal gas
Ideal gases have no attractive or repulsive forces, particles has significant volume and particles and not be liquified or solidified. All of these things are not true for real gases.
Define aqueous solution
Water samples containing dissolved substances
Define solvent
dissolving medium
Define solute
dissolved particle
Define electrolyte
compounds that conduct electricity (ionic cmpds)
Define suspension
mixtures from which particles settle out upon standing ex: muddy water
Define colloid
contains particles that are intermediate in size between suspension and solution
Define emulsion
colloidal dispersion of liquids in liquids
Define solubility
the amount of a substance that dissolves in a given quantity of a solvent at a given temp to produce a saturated solution
What are the 3 colligative properties?
1. vapor pressure lowering
2. freezing point depression
3. boiling point elevation
Define thermochemistry
the study of energy changes that occur during chemical reactions and changes of state
Define thermochemistry
the study of energy changes that occur during chemical reactions and changes of state
Define specific heat capacity
amount of heat it takes to raise the temp of 1g of substance 1 degree C
Define Arrhenious acids and bases
Acids are hydrogen containing compounds that ionize to yield hydrogen ions in aqueous solution. Bases are compounds that ionize to yield hydroxide ions in aqueous solution.
What are the 6 strong acids?
HCl, H2SO4, HNO3, HBr, HI, HClO4
What are the 5 strong bases?
Ca(OH)2, Ba(OH)2 NaOH, KOH, Sr(OH)2
What is the formula for the hydronium ion?
What is a substance that can act as an acid or a base?