The Chemistry Book

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Vocabulary lists are available for download in the MS-Word format. All Vocabulary Sorted by Units Unit 0 Unit 1 Unit 2 Unit 3 Unit 4 Unit 5 Sorted by Standards Introduction to Chemistry Matter Standard 1 Standard 2 Standard 3 Standard 4 Standard 5 Standard 6 Standard 7 Standard 8 Standard 9 Standard 10 Standard 11

Standard 3

The conservation of atoms in chemical reactions leads to the principle of conservation of matter and the ability to calculate the mass of products and reactants.

Atomic mass

the average mass of an atom of a chemical element.

Avogadro’s number

This number (Avogadro's number) is 6.023 X 10²³. It is the number of molecules of any gas present in a volume of 22.41 L and is the same for the lightest gas (hydrogen) as for a heavy gas such as carbon dioxide or bromine.

Balanced equations

An equation for a chemical reaction in which the number of atoms for each element in the reaction and the total charge are the same for both the reactants and the products. In other words, the mass and the charge are balanced on both sides of the reaction.

Chemical equation

a representation of a chemical reaction with reactants on the left and the products on the right with arrows or an equal sign separating the reactants and products.

Chemical formula

A representation of a molecule in which the symbols for the elements are used to indicate the types of atoms present and subscripts are used to show the relative numbers of atoms.

Chemical reaction

The mixing of two or more substances (reactants) mix together and change into a new substance (product).

Coefficients

interegers in a balenced equation

Denominator

The expression written below the line in a common fraction that indicates the number of parts into which one whole is divided.^[1]

Dimensional analysis

Dimensional Analysis (also called Factor-Label Method or the Unit Factor Method) is a problem-solving method that uses the fact that any number or expression can be multiplied by one without changing its value.

Equation

A representation of a chemical reaction, usually written as a linear array in which the symbols and quantities of the reactants are separated from those of the products by an equal sign, an arrow, or a set of opposing arrows.^[2]

Exponents

short-hand notation for writing very large or very small numbers ^[3]

Grams

is a metric unit that can be used to express the mass of something in.

Isolation of variables

setting the variable that is being solved for aside so that the equation may be solved

Isotopes

Atoms with the same number of protons but a different number of neutrons

Mass-to-mole

converting from grams to moles. example: 11.2g NaCl x (1mol NaCl / 58.5g NaCl) = 0.191 mol NaCl ^[4]

Metric conversions

Molar mass (formula units)

A number equal to the sum of the atomic masses of an atom in the molecule

Mole (mol)

The number equal to the number of carbon atoms in exactly 12 grams of pure C: Avoadro's number. One mole represents 6.022×10²³ units.

Molecular mass

Molecular weight

The mass in gram of one mole of a substance.

Mole-to-mass

Oxidation

An increase in oxidation state (a loss of electron).

Oxidation number

the oxidation number of an atom is the charge that atom would have if the compound was composed of ions.

Oxidation-reduction reactions

Oxidation-reduction reactions, also known as redox reactions, are chemical processes in which electrons are transferred from one atom, ion, or molecule to another. Explosions, fires, batteries, and even our own bodies are powered by oxidation-reduction reactions. When iron rusts or colored paper bleaches in the sun, oxidation-reduction has taken place.

Percent yield

the actual yield of an experiment divided by the theoretical yield and multiplied by 100

Principle of conservation of matter

a fundamental principle of classical physics that matter cannot be created or destroyed in an isolated system

Products

a substance resulting from a chemical reaction. It is shown to the right of the arrown in a chemical equation. ^[5]

Reactants

The starting materials in a chem reaction

Reduction

Rules of significant digits

1. Digits from 1-9 are always significant.
2. Zeros between two other significant digits are always significant
3. One or more additional zeros to the right of both the decimal place and another significant digit are significant.
4. Zeros used solely for spacing the decimal point (placeholders) are not significant.

Scientific notation

Scientific notation is used to express very large or very small numbers. A number in scientific notation is written as the product of a number (integer or decimal) and a power of 10. The number has one digit to the left of the decimal point. The power of ten indicates how many places the decimal point was moved.

Stoichiometry

The study of the relationships or ratios between two or more substances undergoing a physical or chemical change

Stoichiometric calculations

1.Calculation of the quantities of reactants and products in a chemical reaction. 2.The quantitative relationship between reactants and products in a chemical reaction.

Subscripts

A distinguishing character or symbol written directly beneath or next to and slightly below a letter or number

Theoretical yield

Units

quantity of measurement that helps identify the measurement that was used

Volume

Nomenclature

Anions

A negatively charged ion

Binary nonmetal-nonmetal

Cations

A positively charged ion

Inorganic nomenclature

oxyanions

An oxyanion or oxoanion is a negatively charged polyatomic ion that contains oxygen. Oxyanions can be viewed as the conjugate base of a corresponding oxyacid, although both components are not necessarily stable. Probably the best known oxyanion is DNA. The most extensive family of oxyanions are the polyoxomolybdates.

Polyatomic

An electrically charged species formed by covalent bonding of atoms of two or more different elements, usually nonmetals, for example, the ammonium ion (NH₄⁺)^[6]

References