Question | Answer |
The study of the structure, properties, and composition of substances, and the changes that substances undergo. | Chemistry |
The study of compounds that contain the element Carbon. | Organic Chemistry |
Primarily the study of substances that do not contain the element Carbon. | Inorganic Chemistry |
The study of the composition of substances. | Analytical Chemistry |
The study of the theoretical basis of chemical behavior, relying on mathematics and physics. | Physical Chemistry |
The study of the composition and behavior of substances in living organisms. | Biochemistry |
The method of inquiry involving observation, experiments, hypothesis, and broad explanations called theories. | Scientific method |
Information obtained through the senses; observation in science often involves a measurement. | Observation |
A proposed explanation for observations. | Hypothesis |
A carefully controlled, repeatable procedure for gathering data to test a hypothesis. | Experiment |
A thoroughly tested model that explains why experiments give certain results. | Theory |
A concise statement that summarizes the results of many observations and experiments. | Scientific Law |
Anything that takes up space and has mass. | Matter |
The amount of matter that an object contains; the SI base unit of mass is the kilogram. | Mass |
A quality of a substance that can be observed or measured without changing the substance’s chemical composition. | Physical property |
A matter that has a definite shape and volume. | Solid |
A form of matter that flows, has a fixed volume, and takes the shape of its container. | Liquid |
Matter that has no definite shape or volume; it adopts the shape of its container. | Gas vapor |
An alteration of a substance that does not affect its chemical composition. | Physical change |
A property that depends upon the amount of material in a sample. | Extensive property |
A property that does not depend on the size of the sample. Melting points, boiling points, colour, conductivity, and density are examples. | Intensive property |
The ability of a substance to undergo chemical reactions and to form new substances. | Chemical property |
A physical blend of two or more substances that are not chemically combined. | Mixture |
A mixture that is not uniform in composition; its components are readily distinguished. | Heterogeneous mixture |
A mixture that is uniform in composition; its components are not readily distinguished. | Homogeneous mixture |
A homogeneous mixture. | Solution |
The changing of substances to other substances by the breaking of bonds in reactants and the formation of bonds in products. | Chemical reaction |
Starting substances in a chemical reaction. | Reactants |
Substances formed in a chemical reaction. | Products |
Mass can neither be created or destroyed in an ordinary chemical or physical process. | Law of Conservation of Mass |
A measurement that gives descriptive, non-numeric results. | Qualitative measurements |
A measurement that gives definite, usually numeric results. | Quantitative measurements |
The expression of numbers in the form N x 10n where N is equal to or greater than 1 and less than 10 N is an integer. | Scientific notation |
The closeness of a measurement to the true value of what is being measured. | Accuracy |
Describes the closeness, or the reproducibility, of a set of measurements taken under the same conditions. | Precision |
All the digits that can be known precisely in a measurement, plus a last estimated digit. | Significant figures |
The percent that a measured value differs from an accepted value. | Percent error |
The ratio of the mass of an object to its volume. | Density |
The measure of the average kinetic energy of particles in matter; temperature determines the direction of heat transfer. | Temperature |
A technique of problem solving that uses the units that are part of a measurement to help solve the problem. | Dimensional analysis |
A negatively charged subatomic particle. | Electron |
A positively charged subatomic particle found in the nucleus of an atom. | Proton |
A subatomic particle with no charge and a mass of 1 amu; found in the nucleus of the atom. | Neutron |
The dense central portion of an atom, composed of protons and neutrons. | Nucleus |
The number of protons in the nucleus of an atom of an element. | Atomic number |
The total number of protons and neutrons in the nucleus of an atom. | Mass number |
Atoms of the same element that have the same atomic number but different atomic masses due to a different number of neutrons. | Isotopes |
The weighted average of the masses of the isotopes of an element. | Atomic mass |
When the elements are arranged in order of increasing atomic number, there is a periodic repetition of their physical and chemical properties. | Periodic law |
A horizontal row of elements in the periodic table. | Period |
The vertical column of elements in the periodic table; the constituent elements of a group have similar chemical and physical properties. | Group |
Group A elements on the periodic table; together , these elements, which have only partially filled outermost s and p sublevels, illustrate the entire range of chemical properties. | Representative elements |
One of a class of elements that includes a large majority of the known elements; metals are characteristically lustrous, malleable, ductile, and good conductors of heat and electricity. | Metals |
Any metal in Group 1A of the periodic table. | Alkali metals |
Any metal in Group 2A of the periodic table. | Alkaline earth metals |
Group B element characterized by addition of electrons to d suborbitals. | Transition metals |
An element in the lanthanide and actinide series; characterized by addition of electrons to f orbitals. | Inner transition metals |
One of a class of elements that are not lustrous and are generally poor conductors of heat and electricity; nonmetals are grouped on the right side of the periodic table. | Nonmetals |
Any member of the nonmetallic elements in Group 7A of the periodic table. | Halogens |
Any member of a group of gaseous elements in Group 0 of the periodic table; the s and p sublevels of their outermost energy level are filled. | Noble gases |
One of a class of elements having properties intermediate to metals and nonmetals. | Metalloids |
A compound that is composed of molecules. | Molecular compouds |
An atom or group of atoms that has a positive or negative charge. | Ions |
Any atom or group of atoms with a positive charge. | Cation |
Any atom or group of atoms with a negative charge. | Anion |
A compound composed of positive and negative ions. | Ionic compounds |
A chemical formula that shows the actual number and kinds of atoms present in a molecule of a compound. | Molecular formula |
The lowest whole-number ratio of ions in an ionic compound; in magnesium chloride, the ratio of magnesium ions to chloride ions is 1:2 and the formula unit is MgCl2 | Formula unit |
A single atom with a positive or negative charge as a result of losing or gaining valence electrons. | Monatomic ions |
A tightly bound group of atoms that behaves as a unit and carries a charge. | Polyatomic ions |
The amount of a substance that contains 6.02 x 1023 representative particles of that substance. | Mole |
The number of representative particles contained in one mole of a substance; equal to 6.02 x 1023 particles. | Avogadro’s number |
The mass, in grams, of one mole of atoms in a monatomic element; it is numerically equal to the atomic mass in amu. | Gram atomic mass |
The mass, in grams, of one mole of a molecular substance. | Gram molecular mass |
The mass of one mole of an ionic compound. | Gram formula mass |
An expression representing a chemical reaction; the formulas of the reactants (on the left) are connected by an arrow with the formulas for the products (on the right). | Chemical equation |
A chemical equation that does not indicate the relative amounts of reactants and products. | Skeleton equation |
A small whole number that appears in front of a formula in a balanced chemical equation. | Coefficients |
A chemical equation in which mass is conserved; each side of the equation has the same number of atoms of each element. | Balanced equation |
A substance that increases the rate of reaction by lowering the activation-energy barrier; the catalyst is not used. up. | Catalyst |
A chemical change in which two or more substances react to form a single new substance; also called a synthesis reaction. | Combination reaction |
A chemical change in which a single compound is broken down into two or more simpler products. | Decomposition reaction |
A chemical change in which one element replaces a second element in a compound; also called a displacement reaction. | Single-replacement reaction |
A chemical change that involves an exchange of positive ions between two compounds. | Double-replacement reaction |
A chemical change in which oxygen reacts with another substance, often producing energy in the form of heat and light. | Combustion reaction |
Electrons enter orbitals of lowest energy first. | Aufbau Principle |
| Pauli Exclusion Principle |
When electrons occupy orbitals of equal energy, one electron enters each orbital until all orbitals contain one electron with their spins parallel. | Hund’s Rule |