Chemistry Vocab

Front 1

Atom

Back 1

The smallest part of an element that still retains the properties of that element.

Front 2

Accuracy

Back 2

How close a result comes to the true value.

Front 3

Atomic Theory

Back 3

The scientific theory that describes the structure, behavior, and other properties of the atom and its component parts.

Front 4

Avogadro's Number

Back 4

The number of units in a mole, defined as 6.022x10^23 particles, which is the number o atoms determined experimentally to be found in 12 grams of carbon-12.

Front 5

Chemical Property

Back 5

A property that can only be observed when a chemical change occurs.

Front 6

Density

Back 6

A measure of mass per volume. The average density of an object equals its total mass divided by its total volume.

Front 7

Dimensional Analysis

Back 7

A method for comparing the dimensions of the physical quantities occurring in a problem to find relationships between the quantities.

Front 8

Electron

Back 8

A particle that represents a unit charge of 11 and a mass of 0 a.m.u.

Front 9

Element

Back 9

Matter which exhibits definite physical and chemical properties unique to itself and different from all other forms of matter and cannot be decomposed into simpler forms of matter.

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Mass

Back 10

A measure of the amount in an object. Mass is usually measured in grams or kilograms.

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Molar Mass

Back 11

The sum of the total mass in grams of all atoms that make up a mole of a particular molecule. The unit used to measure is grams per mole.

Front 12

Mole

Back 12

A standard scientific unit for measuring large quantities of atoms or molecules. Defined as 6.022x10^23 particles, which is the number of atoms determined experimentally to be found in 12 grams of carbon-12. The number of units in a mole also bears the name Avogadro's Number.

Front 13

Molecule

Back 13

A particle made of nonmetal atoms covalently bonded together to form a distinct particle.

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Neutron

Back 14

The particle that has no charge and has a mass of 1 a.m.u.

Front 15

Nuclear Fusion

Back 15

The process whereby two small nuclei are combined to form one larger nucleus with release of a huge amount of energy derived from the conversion of a tiny bit of mass into energy.

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Physical Property

Back 16

A property that can be observed without a chemical change occurring.

Front 17

Precision

Back 17

The place to which a measurement was made.

Front 18

Proton

Back 18

A particle that represents a unit charge of +1 and a mass of 1 a.m.u.

Front 19

Significant Figures

Back 19

The number of digits actually recorded by a measuring device during a measurement.

Front 20

Substance

Back 20

Matter which has a specific composition and specific properties.

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Volume

Back 21

The space occupied by a gas, liquid, or solid.

Front 22

Alkali Earth Metals

Back 22

An element in group 1 of the periodic table. These elements are extremely reactive.

Front 23

Alkali Metals

Back 23

An element in group 2 of the periodic table. These elements are very reactive.

Front 24

Atomic Number

Back 24

The number that identifies an element, equal to an atom's number of protons.

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Atomic Radius

Back 25

The size of an atom.

Front 26

Diatomic Molecule

Back 26

A nonmetal atom that forms one or more nonpolar covalent bonds with another atom of the same element to form a molecule consisting of the two atoms when there is no other element to bond with. Elements that do this are Br, I, N, Cl, H , O, and F.

Front 27

Electronegavitity

Back 27

A measure of the tendency of an atom to attract a bonding pair of electrons.

Front 28

Emit

Back 28

To give off something.

Front 29

Family (group)

Back 29

A column of elements in the periodic table of the chemical elements.

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Halogens

Back 30

An element in group 17 of the periodic table. These elements are extremely reactive.

Front 31

Inert

Back 31

A substance that is not chemically reactive.

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Ionization Energy

Back 32

The amount of energy required to remove the most loosely bound electron.

Front 33

Lewis Dot Diagram

Back 33

A structural representation of a molecule where dots are used to show electron position around the atoms and lines or dot pairs represent covalent bonds between atoms.

Front 34

Mass Number

Back 34

The sum total of the protons and neutrons in an atom.

Front 35

Metalloids

Back 35

Elements that exhibit properties of both metals and nonmetals.

Front 36

Noble Gases

Back 36

An element in group 18 of the periodic table. These elements are non reactive.

Front 37

Nonmetals

Back 37

Elements that have high electronegativity and ionization Energy and small radius that tend to gain or share electrons to form chemical bonds.

Front 38

Octet

Back 38

A chemical rule that atoms of main-group elements tend to combine so that each atom has eight electrons in its valence shell, giving it the same electronic configuration as a noble gas.

Front 39

Orbital

Back 39

Regions of space around the nucleus of an atom where an electron is likely to be found.

Front 40

Period (series)

Back 40

Rows across the periodic table that denote elements with the same number of principle energy levels.

Front 41

Periodic Table

Back 41

A table of the chemical elements arranged in order of atomic number, usually in rows, so that elements with similar atomic structure (and hence similar chemical properties) appear in vertical columns.

Front 42

Transition Metals

Back 42

An element in groups 3-12 of the periodic table. Many of these elements have colored ions.

Front 43

Avogadro's Hypothesis

Back 43

Equal volumes of two ideal gases under the same conditions of temperature and pressure will contain equal numbers of molecules.

Front 44

Boiling

Back 44

The transition of a liquid into a gas at the boiling point.

Front 45

Calorimetry

Back 45

The measurement of energy change between potential and kinetic energy by measuring the temperature change induced on a measured mass of water in a calorimeter.

Front 46

Change

Back 46

A transformation from one condition of matter to another.

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Condensing

Back 47

The transition of a gas into a liquid at the boiling point.

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Deposition

Back 48

The transition of a gas into a solid.

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Endothermic

Back 49

The conversion of kinetic energy into potential energy.

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Equilibrium

Back 50

The condition that exists when the rates of two opposing changes are equal.

Front 51

Evaporating

Back 51

The transition of the surface molecules of a liquid into a gas below the boiling point.

Front 52

Exothermic

Back 52

The conversion of potential energy into kinetic energy.

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Freezing

Back 53

The transition of a liquid into a solid at the freezing point.

Front 54

Gas

Back 54

A phase of matter characterized by the complete dissociation of matter particles from each other with the distances between the particles very large in comparison to the size of the particles and no attractive forces between them.

Front 55

Heat of Fusion

Back 55

The energy required to melt a gram of solid at its melting point.

Front 56

Heat of Vaporization

Back 56

The energy required to boil a gram of liquid at its boiling point.

Front 57

Ideal Gas

Back 57

A gas in which the molecules are infinitely small and far apart, the molecules travel with a straight line motion, all collisions have no net loss of energy (elastic), there are no attractive forces between molecules and the speed of the molecules is directly proportional to the Kelvin temperature. Gases are most ideal at high temperature and low pressure.

Front 58

Kinetic Energy

Back 58

Energy of motion.

Front 59

Liquid

Back 59

A phase of matter characterized by matter loosely organized yet kept together by intermolecular or ionic attractive forces.

Front 60

Melting

Back 60

The transition of a solid into a liquid at the melting point.

Front 61

Potential Energy

Back 61

Stored energy, often stored in chemical bonds.

Front 62

Pressure

Back 62

Force exerted over an area.

Front 63

Solid

Back 63

A phase of matter characterized by matter arranged in regular geometric patterns called crystal lattices with only vibration motion, no relative motion.

Front 64

Specific Heat

Back 64

The energy required to heat one gram of a substance by one kelvin.

Front 65

Sublimation

Back 65

The transition of a solid into a gas.

Front 66

Temperature

Back 66

The average kinetic energy of a sample or system.

Front 67

Vapor Pressure

Back 67

The pressure exerted by vapor in a vapor-liquid mixture in a closed system at equilibrium.

Front 68

Vapor-Liquid Equilibrium

Back 68

A system where the rate of evaporation equals the rate of condensing.

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Anion

Back 69

A negatively charged ion.

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Binary Compound

Back 70

A compound that consists of two elements.

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Cation

Back 71

A positively charged ion.

Front 72

Covalent Compound

Back 72

Compounds consisting of two nonmetals (or a nonmetal and a metalloid) that are covalently bonded.

Front 73

Electronegativity Difference

Back 73

The difference in electronegativity between two elements in a bond.

Front 74

Empirical Formula

Back 74

The simplest whole number mole ration of elements in a compound, used to write the formulas of ionic compounds.

Front 75

Formula Mass

Back 75

The sum of the atomic masses of an element or compound, measured in grams/mole. Reported to the nearest tenth of a gram per mole.

Front 76

Intermolecular Attractive Force

Back 76

The forces that hold molecules together in the solid and liquid phase. These are the forces that must be overcome to melt or boil a substance. Also called "van der Waal's forces."

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Ionic Bond

Back 77

A bond formed when a metal atom loses its valence electrons to a nonmetal atom, forming positive and negatively charged ions that attract each other.

Front 78

Ionic Compound

Back 78

Compounds consisting of a metal and a nonmetal that are ionically bonded in a whole number ratio.

Front 79

Molecular Formula

Back 79

The actual number of nonmetal atoms covalently bonded together to form a distinct particle.

Front 80

Monatomic Ion

Back 80

An ion that consists of one element.

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Oxidation

Back 81

The loss of electrons from an atom or ion.

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Polyatomic Ion

Back 82

An ion formed by atoms bonding together in such a way that a net charge is formed.

Front 83

Stock System

Back 83

A method for naming ions of elements that can form more than one possible positive charge by using a Roman numeral after the Ion name to denote the ion's charge.

Front 84

Ternary Compound

Back 84

A compound that consists of three or more elements, usually containing a polyatomic Ion.

Front 85

Coefficient

Back 85

A number placed in front of a formula to balance a chemical reaction.

Front 86

Decomposition

Back 86

A redox reaction in which a compound breaks up to form two elements.

Front 87

Double Replacement

Back 87

A solution in which the positive Ion of one compound combines with the negative Ion of the other compound to form a precipitate, and the other ions remain dissolved in solution.

Front 88

Law of Conservation of Charge

Back 88

Charge cannot be created or destroyed by physical or chemical change. This is the basis for writing chemical formulas and half reactions, and balancing redox ionic reactions.

Front 89

Law of Conservation of Energy

Back 89

Energy cannot be created or destroyed by physical or chemical change. This is the basis for calculating the heat of reaction.

Front 90

Law of Conservation of Mass

Back 90

Matter cannot be created or destroyed by physical or chemical change. This is the basis for balancing chemical equations.

Front 91

Mole Ratio

Back 91

The whole-number ratio between components of a balanced chemical reaction.

Front 92

Precipitate

Back 92

An insoluble solid that is formed either in a double-replacement reaction as excess solute added to a saturated solution.

Front 93

Product

Back 93

The substances that are formed by a chemical reaction, designated as the right side of a chemical equation.

Front 94

Reactant

Back 94

The substances that reacted together, designated as the left side of a chemical equation.

Front 95

Reaction

Back 95

A chemical change where reactants are turned into products.

Front 96

Redox Reaction

Back 96

A reaction in which element is oxidized and another element is reduced.

Front 97

Reduction

Back 97

The gain of electron(s), causing the oxidation number of a species to become more negative.

Front 98

Single Replacement

Back 98

A redox reaction in which an element replaces an ion in a compound.

Front 99

Spectator Ion

Back 99

An ion that does not participate in the chemical reaction. In a redox reaction, it is the Ion whose charge doesn't change. In a double replacement reaction, they are the ions that remain dissolved in solution.

Front 100

Stiochiometry

Back 100

The mathematics of mole relationships.

Front 101

Synthesis

Back 101

A redox reaction in which two elements combine to form a compound.

Front 102

Molar Volume

Back 102

The volume that one mole of a gas occupies at STP, defined as 22.4L.

Front 103

Activated Complex

Back 103

The species that are formed and decomposed during the mechanism, also called the intermediate.

Front 104

Activation Energy

Back 104

The energy that must be added to the reactants to allow them to react and form the activated complex.