MATTER MATTERS Flashcards
Pure Substance
a sample of matter, either an element or a compound, that consists of only one component with definite physical and chemical properties and a definite composition.
Boyle’s Gas Law
an experimental gas law which describes how the pressure of a gas tends to decrease as the volume of a gas increases. Shown by the equation P1V1 = P2V2.
Charles’s Gas Law
an experimental gas law which describes how gases tend to expand when heated. Shown by the equation V1 / T1 = V2 / T2.
Ideal Gas Law
a law that describes the relationships between measurable properties of an ideal gas. The law states that P × V = n × (R) × T, where P is pressure, V is volume, n is the number of moles of molecules, T is the absolute temperature, and R is the gas constant.
Phase change diagram
a graph, usually using temperature, pressure, and composition as coordinates, indicating the regions of stability of the various phases of a system.
Sublimation
a physical process that results in the phase transition of a substance from a solid directly to a gas without first becoming a liquid.
Heat of fusion
the heat absorbed per unit mass of a given solid at its melting point that completely converts the solid to a liquid at the same temperature.
Phase change
a change from one state (solid or liquid or gas) to another without a change in chemical composition.
Chemical change
a process where bonds are broken and new bonds are formed between different atoms.
Density
the ratio of the object’s mass to its volume. The formula is d = m / V.
Physical change
a usually reversible change in the physical properties of a substance, as size or shape.
Element
a substance composed of atoms having an identical number of protons in each nucleus. Elements cannot be reduced to simpler substances by normal chemical means.
Matter
the substance that is seen all around us, consists of anything that has mass and volume.
Mixture
a composition of two or more substances that are not chemically combined with each other and are capable being separated.
Compound
a pure, homogeneous substance consisting of atoms or ions of two or more different elements in definite proportions that cannot be separated by physical means. A compound usually has properties unlike those of its constituent elements.
