Chemistry EOC Review
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activation energy
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the minimum amount of energy required by reacting particles in order to form the activated complex and lead to a reaction
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accuracy
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refers to how close a measured value is to an accepted value
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alloy
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a mixture of elements that has metallic properties
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alpha particle
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a particle with two protons and two neutrons, with a 2+ charge; is equivalent to a helium-4 nucleus
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atom
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the smallest particle of an element that retains all the properties of that element; is electrically neutral, spherically shaped, and composed of protons, neutrons, and electrons
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Arrhenius Model
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states that an acid is a substance that contains hydrogen and ionizes to produce hydrogen ions, and a base is a substance that contains hydroxide grop and produces hydroxide ions
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aufbau principle
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states that each electron occupies the lowest energy orbital available
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Avogadro's number
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the number 6.02 x 10^23 which is representative of the number of particles in a mole
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amplitude
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the height of the wave from origin to crest, or from the origin to a trough
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average atomic mass
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determined by multiplying each number isotope by the percent, and adding all of the products
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anion
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an ion that has a negative charge; forms when valence electrons are added to the outer energy level
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atomic number
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the number of protons in an atom
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beta particle
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a high speed electron with a 1- charge that is emitted during radioactive decay
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barometer
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an insturment tha tis used to measure atmospheric pressure
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Boyle's Law
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states that volume of a given amount of gas held at a constant temp varies inversely with the pressure
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Bronsted Lowry model
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model of acids and bases in which an acid is a hydrogen ion donor and the base is a hydroxide ion acceptor
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cation
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an ion that has a positive charge; forms when valence electrons are removed, giving the in a stable electron configuration
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chemical change
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the process involving one or more substances changing into new substances; also called a chemical reaction
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chemical property
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the ability or inability of a substance to comine with or change into one or more new substances
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Charles's Law
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states that volume of a given mass of gas is directly proportional to its kelvin temp at constant pressure
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catalyst
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a substance that increases the rate of a chemical reaction by lowering the activation energy
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coeffecient
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the number written in front of a reactant or product
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combined gas law
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a single law combing boyles, charles, and lussacs laws that states the relationship among pressure, volume, and temp of a fixed amount of gas
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combustion reaction
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a chemical reaction that occurs when a substance reacts with oxygen, releasing energy in the form of heat and light; hydrocarbon + oxygen yields carbon dioxide + water
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covalent bond
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a chemical bond that results from the sharing of valence electrons; electronegativity difference is less than 1.7; two or more nonmetals
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cathode ray
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J.J. Thompson's experiment in which he discovered electrons and protons; created the plum pudding model
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compound
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combination of two or more elements
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Dalton's atomic theory
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5 part theory; right-everything is made of atoms, atoms combine and separate, and atoms form simple whole number ratios. wrong- you can't divide and atom, and he didn't know about isotopes
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Dalton's law of partial pressures
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states that the total pressure of amixture of gases is equal to the sum of the pressures of all the gases in the mixtures
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decomposition reaction
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a chemical reaction that occurs when a single compound breaks down into two or more elemtns or new compounds
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delocalized electrons
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the electrons involved in metallic bonding that are free to move easily from one atom to the next throughout the metal and are not attached to any particular atom
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deposition
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when substance changes from gas/vapor to a solid, without first becoming liquid
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double replacement reaction
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a chemical reaction that involves the exchange of positive ions between two compounds and produces either a precipitate, a gas, or water
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dependent variable
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the variable whose value depends on the independent variable
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dipole-dipole forces
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the attractions b/w oppositely charged regions of polar molecules
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electron
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a negatively charged, fast moving particle found in the empty space surrounding nucleus
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electron configuration
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the arrangement of electrons in an atom
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electronegativity
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indicates the relative ability of an elements atoms to attract electrons in a chemical bond
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electron sea model
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shows that all metal atoms contribute their valence electrons to form a sea of electrons
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element
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a pure substance that cannot be broken down into simpler subtances by physical or chemical means
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endothermic
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a chemical reaction in which a grater amount of energy is required to break the existing bonds than is released when the new bonds form in the product molecules; heat absorbed
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enthalpy
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the heat content of a system at constant pressure
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entropy
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a measure of the randomness of the particles of the system
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exothermic
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a chemical reaction in which more energy is released than is required to break bonds in the initial reaction; heat released
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Gay-Lussac's law
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states that the pressure of a given mass varies directly with the temperature when volume remains constant
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gamma rays
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high energy radiation that has no electrical charge and no mass, is not deflected by electric or magnetic fields, usually accompanies alpha and beta radiation, and accounts for most of the energy lost during radioactive decay
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heterogenous mixture
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one that does not have a uniform composition and in which the individual substances remain distinct
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homogeneous mixture
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one that has a uniform composition throughout and always has a single pahse; also called a solution
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Hund's rule
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states that single electrons with the same spin must occupy each equal energy orbital before additional electrons with opposite spins can occupy the same orbital
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hydrogen bond
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a strong dipole dipole attraction bw molecules that contain a hydrogen atom bonded to a small, highly electronegative atom with at least one lone electron pair; usually N, O, F
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hydrate
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a compound that has a specific number of water molecules bound to its atoms
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ideal gas law
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PV=nRT; temp in kelvin, R depends on P units
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independent variable
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variable that the experimenter plans to change
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isotopes
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atoms of the same element with the same number of protons, but different number of neutrons
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ionic bond
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metal with a nonmetal; hard, rigid, brittle solids, high melting and boiling points, conducts electricity in the aqueous and molten states
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insoluable
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describes a substance that cannot be dissolved in a given solvent
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immiscible
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describes two liquids that can be mixed together but separate shortly after you cease mixing them
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ionization energy
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the energy required to remove an electrn from a gaseous atom; generally increases left to right, and decreases tope to bottom. (florine=greatest)
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joule
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the SI unit of heat and enegy
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kinetic molecular theory
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explains the properties of gases in terms of the energy, size, and motion of thier particles
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law of conservation of energy
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states that in any chemical or physical process, energy may change from one form to another, but it is neither created, nor destroyed
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law of conservation of mass
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in any physical change or chemical reaction, mass is conserved; mass can be neither created nor destroyed
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law of conservation of charge
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states that charge can be transferred from one object to another but cannot be created or destroyed
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Lewis Dot structure
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a model that uses electron dot structures to show how electrons are arranged in molecules; lines represent bonding pairs
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limiting reactant
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reactant that is totally consumed during a chemical reaction, limits the exten of the reaction and dtermines the amount of product
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matter
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anything that has mass and takes up space
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mixture
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a physical blend of two or more pure substances in any proportion in which each
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molecule
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forms when two or more atoms covalently bond and is lower in potential energy than its constituent atoms
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mass number
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the number after the elements name, representing the sum of its protons and neutrons
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metal
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left side of periodic table; good conductor of heat and electricity, ductile, malleable, generall shiny
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metalloid
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an element that has properties of both metals and nonmetals; found along the steps lines on periodic table
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miscible
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describes two liquids that are soluable in each other
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metallic bond
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the attraction of a metallic cation for delocalized electrons
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molecular formula
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a formula that specifies the actual number of atoms of each element in one molecule or formula unit of the substance; done after empirical formula
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empirical formula
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percent to mass, mass to mole, divide by small, multiply till whole
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heat of fusion
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the amount of heat required to melt one mole of a solid substance; 334j/g; Q=mHf
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heat of vaporization
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the amount of heat required to evaporate one mole of a liquid; 2260j/g; Q=mHv
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molarity
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the number of moles of solute dissolved per liter of solution; moles of solute/liters of solution
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molar mass
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the mass in grams of one mole of any pure substance
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molar volume
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for a gas, the volume that one mole occupies; 22.4 at one mole
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mole
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the SI base unit used to measure the amount of a substance
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neutron
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a neutral subatomic particle in an atoms nucleus that has a mass nearly equal to that of a proton
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group
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the vertical column of elements in the periodic table
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fission
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the splitting of a nucleus into smaller, more stable fragments
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fusion
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the process of binding smaller atomic nuclei into a single larger and more stable nucleus
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noble gas configuration
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electron configuration in which you incorporate the noble gas to replace a group of configurations
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neutralization reaction
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a reaction in which an acid and base react in aqueous solution to produce a salt and water
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nonmetal
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elements on the right side of periodic table; generally dull gases, brittle solids, and poor conductors of heat and electricity
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octet rule
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states that atoms lose, gain, or share electrons in order to acquire a full set of eight valence electrons
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oxidation number
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the positive or negative charge of a monatomic ion
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Pauli exclusion principle
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states that a maximum of two electrons may occupy a single atomic orbital, but only if the electrons have opposite spins
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percent yield
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the ratio of actual yield to theoretical yield expressed as a %; actual/theoretical x 100
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percent error
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the ratio of an error to an accepted value
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pH
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the negative logarithm of the hydrogen ion concentration of a solution; 1-14; 7 is neutral; 0-6=acid; 8-14=base
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period
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a horizontal row of elements in the periodic table
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physical change
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a type of change that alters the physical properties of a substance but does not change its composition
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physical property
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A characteristic of a matter that can be observed without changing the samples composition; ex. density, color, taste, etc
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photon
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a particle of electromagnetic radiation with no mass that carries a quantum of energy
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polar covalent
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a type of bond that forms when electrons are not shared equally
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precipitate
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a solid produced during a chemical reactin in a solution
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precision
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refers to how close a series of measurements are to one another; precise measurements show little variation over a series of trials but may not be accurate
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product
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a substance formed during a chemical reaction
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proton
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a subatomic particle in an atoms nucleus with a positive charge a 1+
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reactant
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the starting substance in a chemical reaction
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excess reactant
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a reactant that remains after a chemical reactant starts
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saturated
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contains the maximum amount of dissolved solute for a give amount of solvent at a specific temp and pressure
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single replacement reaction
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a chemical reaction that occurs when the atoms of one element replace the atoms of another element in a compound
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solute
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a substance dissolved in a solution
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soluble
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describes a substance that can be dissolved in a give solvent
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solvent
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the substance that dissolves a solute to form a solution
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solution
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a uniform mixture that may contain solids, liquids, or gases
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strong acid
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an acid that ionizes completely in aqueous solution
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strong base
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a base that dissociates entirely into metal ions and hydroxide ions in aqueous solution
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sublimation
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solid changes to directly to a gas w/o becoming liquid first
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supersaturated
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contains more dissolved solute than a saturated solution at the same temperatrue
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synthesis reaction
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a chemical reaction in which two or more substances react to yield a single product
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temperature
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a measure of the average kinetic energy of the particles in a sample of matter
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theoretical yield
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the maximum amount of product that can be produced from a given amount of reactant
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unsaturated solution
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contains less dissolved solute for a given temp and pressure than a saturated solution
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valence electrons
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the electrons in an atoms outermost orbitals; determines the elements chem properties
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wavelength
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the shortest distance between equivalent points on a continous wave
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weak acid
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an acid that ionizes only partially in dilute aqueous solution
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weak base
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a base that ionizaes only partially in dilute aqueous solution to form the conjugate acid of the base and hydroxide ion
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actual yield
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the amount of product actully produced when a chemical reaction is carried out in an experiment
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heat
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a form of energy that flows from a warmer object to a cooler object
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Q=mCpT
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the formula to determine heat
