Honors Chemistry Final

law of conservation of mass

the law that states that mass cannot be created or destroyed in ordinary chemical and physical changes

law of definate proportions

the law that states a chemical compound always contains the same elements in exactly the same proportions by weight or mass

law of multiple proportions

the law that states that when two elements combine to form two or more compounds, the mass of one element that combines with a given mass of the other is in the ratio of small whole numbers

atom

the smallest component of an element having the chemical properties of the element

nuclear forces

the interaction that binds protons and neutrons, protons and protons, and neutrons and neutrons together in a nucleus

atomic number

the number of protons in the nucleus of an atom

isotope

an atom that has the same number of protons as other atoms of the same element do but that has a different number of neutrons

mass number

the sum of the number of neutrons and protons that make up the nucleus of an atom

nuclide

An atom that is identified by the number of protons and neutrons in its nucleus

atomic mass unit

a unit of mass that describes the mass of an atom or molecule

average atomic mass

weighted average of the atomic masses for the isotopes of an element

mole

the SI base unit used to measure the amount of a substance whose number of particles is the same as the number of atoms of carbon in exactly 12g of carbon-12

Avogadro's number

used to find molecules. the number of atoms or molecules in one mole (6.022 x 10^23)

molar mass

the mass in grams of 1 mol of a substance

Electromagnetic radiation

A form of energy that exhibits wavelike behavior as it travels through space

Electromagnetic spectrum

All of the frequencies or wavelengths of electromagnetic radiation

Wavelength

The distance between corresponding points on adjacent waves

Frequency

the number of waves that pass a given point per second

Photoelectric effect

The emission of electrons from a metal when light shines on the metal

Quantum

The minimum amount of energy that can be gained or lost by an atom

Photon

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

Ground state

The lowest energy state of an atom

Excited state

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

Line-emission spectrum

A diagram or graph that indicates the degree to which a substance emits radiant energy with respect to wavelength

Continuous spectrum

The emission of a continuous range of frequencies of electromagnetic radiation

Heisenberg uncertainty principle

It is impossible to know exactly both the velocity and the position of a particle at the same time

Quantum theory

Describes mathematically the wave properties of electrons and other very small particles

Orbital

Three dimensional region around the nucleus that indicates the probable location of an electron

Quantum numbers

Specify the properties of atomic orbitals and the properties of electrons in orbitals.

Principle quantum number

Symbolized by n, indicates the main energy level occupied by the electron

Angular momentum number

Symbolized by l, indicates the shape of the orbital

Magnetic quantum number

Symbolized by m, indicates the orientation of an orbital around the nucleus

Spin quantum number

The quantum number that has only two possible values, +1/2 and -1/2, which indicate the two fundamental spin states of an electron in an orbital

Electron configuration

The arrangement of electrons in an atom

Aufbau principle

An electron occupies the lowest-energy orbital that can receive it

Pauli exclusion principle

No two electrons in the same atom can have the same set of four quantum numbers

Hund's rule

Orbitals of equal energy are each occupied by one electron before any orbital is occupied by a second electron, and all electrons in singly occupied orbitals must have the same spin

Noble gases

The Group 18 elements (He, Ne, Ar, Kr, Xe, Rn)

Noble-gas configuration

An outer main energy level occupied, in most cases, by eight electrons

chemical bonding

combining of atoms of elements to form new substances

ionic bonding

a force that attracts electrons from one atom to another, which transforms a neutral atom into an ion

covalent bonding

chemical bonding that results from the sharing of electron pairs between two atoms

nonpolar-covalent bond

a covalent bond in which the bonding electrons are equally attracted to both bonded atoms

polar-covalent bond

a covalent bond in which a pair of electrons shared by two atoms is held more closely by one atom

molecule

the simplest structural unit of an element or compound

molecular compound

chemical compound whose simplest units are molecules

chemical formula

a combination of chemical symbols and numbers to represent a substance

molecular formula

a chemical formula that shows the number and kinds of atoms in a molecule, but not the arrangement of the atoms

bond energy

the energy required to break the bonds in 1 mol of a chemical compound

electron-dot notation

an electron configuration notation in which only the valence electrons of an atom of the particular element are shown

Lewis structure

a structural formula in which electrons are represented by dots; dot pairs or dashes between two atomic symbols represent pairs in covalent bonds.

structural formula

a formula that indicates the location of the atoms, groups, or ions relative to one another in a molecule and that indicates the number and location of chemical bonds

single bond

a covalent bond in which two atoms share one pair of electrons

multiple bond

a bond in which the atoms share more than one pair of electrons, such as a double bond or a triple bond.

resonance

the bonding in molecules or ions that cannot be correctly represented by a single Lewis structure

ionic compound

a compound composed of ions bound together by electrostatic attraction

formula unit

the collection of atoms corresponding to an ionic compound's formula such that the molar mass of the compound is the same as the mass of 1 mol of formula units

lattice energy

the energy associated with constructing a crystal lattice relative to the energy of all constituent atoms separated by infinite distances

polyatomic ion

an ion made of two or more atoms

metallic bonding

a bond formed by the attraction between positively charged metal ions and the electrons around them

malleability

the ability of a substance to be hammered or beaten into thin sheets

ductility

the ability of a substance to be drawn, pulled, or extruded through a small opening to produce a wire

VESPR theory

the idea that electron pairs repel, molecules adjust their shapes so that valence electrons pairs are as far apart as possible

hybridization

the mixing of two or more atomic orbitals of similar energies on the same atom to produce new orbitals of equal energies

hybrid orbitials

orbitials that have the properties to explain the geometery of chemical bonds between atoms

dipole

a molecule or a part of a molecule that contains both positively and negatively charged regions

hydrogen bonding

the intermolecular force in which a hydrogen atom that is bonded to a highly electronegative atom is attracted to an unshared pair of electrons of an electronegative atom in a nearby molecule

London dispersion forces

the intermolecular attraction resulting from the uneven distribution of electrons and the creation of temporary dipoles

Soluble

Capable of being dissolved

Solvent

The dissolving medium in a solution

Solute

The substance being dissolved in a solution

Suspension

Particles in a solvent are so large that they settle out unless the mixture is constantly stirred oragitated; particles can be separated by passing the mixture through a filter

Colloids

Particles that are intermediate in size between those in solutions and suspensions form mixtures known as colloidal dispersions

Tyndall effect

Light is scattered by colloidal particles dispersed in a transparent medium

Electrolyte

A substance that dissolves in water to give a solution that conducts electric current

Nonelectrolyte

A substance that dissolves in water to give a solution that does not conduct an electric current

Solution equilibrium

The physical state in which the opposing processes of dissolution and crystallization of a solute occur at equal rates

Saturated solution

A solution that contains the maximum amount of dissolved solute

Unsaturated solution

A solution that contains less solute than a saturated solution does and that is able to dissolve additional solute

Supersaturated solution

A solution that contains more dissolved solute than a saturted solution under the same conditions

Solubility

The amount of that substance required to form a saturated solution with a specific amount of solvent at a specified temperature

Hydration

The strong affinity of water molecules for particles of dissolved or suspended substances that causes electrolytic dissociation

Anhydrous

Without water, especially water of crystallization

Immiscible

Liquids that are not soluble in each other (ex. Toluene and water)

Miscible

Liquids that dissolve freely in one another in any proportion (ex. benxene and carbon tetrachloride)

Henry's law

The solubility of a gas in a liquid is directly proportional to the partial pressure of that gas on the surface of the liquid

Effervescence

Rapid escape of a gas from a liquid in which it is dissolved

Solvated

A solute particle that is surrounded by solvent molecules

Enthalpy of solution

The net amount of energy absorbed as heat by the solution when a specific amount of solute dissolves in a solvent.

Molarity

The number of moles of solute per liter of solution

Molality

The concentration of a solution expressed in moles of solute per kilogram of solvent

Concentration

A measure of the amount of solute in a given amount of solvent or solution