Chapters 3 and 4: Matter, Energy, and Atoms

This set of vocabulary flashcards covers the fundamental concepts of matter, energy, and atomic structure discussed in Chapters 3 and 4, including states of matter, conservation laws, and the organization of elements.

Chemistry

Studies the composition, structure, properties, and changes of matter.

Scientific Law

summarizes a large number of observations and results, typically expressed in mathematical terms.

The Scientific Method

a systematic approach used in scientific investigation that involves observation, hypothesis formulation, experimentation, and analysis to draw conclusions.

Scientific Theory

The atomic theory of John Dalton

Matter

Anything that occupies space and has mass.

Molecules

Well-defined structures formed when several atoms bond together.

Solid Matter

A state of matter where atoms or molecules pack close to each other in fixed locations, resulting in a fixed volume and rigid shape.

Crystalline Solid

A solid in which atoms or molecules are arranged in geometric patterns with long-range, repeating order.

Amorphous Solid

A solid in which atoms or molecules do not have long-range order.

Liquid Matter

A state of matter where atoms or molecules are close to each other but are free to move around and by each other, having a fixed volume but assuming the shape of their container.

Gaseous Matter

A state of matter where atoms or molecules are separated by large distances and are free to move relative to one another, making them compressible.

Pure Substance

Matter composed of only one type of atom or molecule.

Mixture

Matter composed of two or more different types of atoms or molecules combined in variable proportions.

Element

A pure substance that cannot be broken down into simpler substances by chemical transformation.

Compound

A pure substance composed of two or more elements in fixed definite proportions that can be decomposed into simpler substances.

Physical Property

A characteristic that a substance displays without changing its composition.

Chemical Property

A characteristic that a substance displays only through changing its composition via a chemical change.

Reactants

The substances present before a chemical change occurs.

Products

The substances present after a chemical change has occurred.

Law of Conservation of Mass

The principle stating that matter is neither created nor destroyed in a chemical reaction.

Energy

The capacity to do work.

Work

The result of a force acting on a distance.

Law of Conservation of Energy

The principle stating that energy is neither created nor destroyed; the total amount of energy is constant.

Joule (J)

The SI unit of energy.

calorie (cal)

A unit of energy defined as the amount required to raise the temperature of $1\,g$ of water by $1\,^{\circ}\text{C}$.

Exothermic Reaction

A chemical reaction in which energy is released.

Endothermic Reaction

A chemical reaction in which energy is absorbed.

Temperature

A measure of the thermal energy (the constant random motion of atoms and molecules) in a substance.

Heat

The transfer or exchange of thermal energy caused by a temperature difference.

Specific Heat Capacity

The quantity of heat required to change the temperature of $1\,g$ of a substance by $1\,^{\circ}\text{C}$, expressed in units of $J/g\,^{\circ}\text{C}$.

Atomic Number (Z)

The number of protons in the nucleus of an atom, which identifies the atom as a particular element.

Metals

Elements on the left side of the periodic table characterized by being good conductors, malleable, ductile, lustrous, and prone to losing electrons.

Nonmetals

Elements on the upper right side of the periodic table that tend to be poor conductors and gain electrons during chemical changes.

Cations

Positively charged particles formed when atoms lose electrons.

Anions

Negatively charged particles formed when atoms gain electrons.

Isotopes

Atoms with the same number of protons but different numbers of neutrons.

Radioactive

A term describing isotopes with unstable nuclei that emit nuclear radiation.