Ch1: Matter & Measurement Flashcards
Accuracy
A measure of how closely measurements agree with the correct answer.
Absolute Zero
The lowest attainable temperature; 0 K on the Kelvin scale and -273.15*C on the Celsius scale.
Aqueous Solution
A solution in which water is the solvent.
Atom
The smallest representative particle of an element.
Celsius Scale
A temperature scale on which water freezes at 0* and boils at 100* at sea level.
Changes of state
Transformations of matter from one state to a different one, for example, from a gas to a liquid.
Chemical Changes
Processes in which one or more substances are converted into other substances; also called chemical reactions.
Chemical Properties
Properties that describe a substance’s composition and it’s reactivity; how the substance reacts or changes into other substances.
Chemistry
The scientific discipline that studies the composition, properties, and transformations of matter.
Compound
A substance composed of two or more elements united chemically in definitely proportions.
Conversion Factor
A ratio relating the same quantity in two systems of units that is used to convert the units of measurement.
Density
The ratio of an object’s mass to its volume.
Dimensional Analysis
The method of problem solving in which units are carried through all calculations. Dimensional Analysis ensures that the final calculation has the desired units.
Electrochemistry
The branch of chemistry that deals with the relationship between electricity and chemical reactions.
Element
A substance consisting of atoms of the same atomic number. Historically defined as a substance that cannot be separated into simpler substances by chemical means.
Extensive Property
A property that depends on the amount of material considered; for example, mass or volume.
Hypothesis
A tentative explanation of a series of observations or of natural law.
Intermolecular Forces
The short-range attractive forces operating between the particles that make up the units of a liquid or solid substance. These same forces also cause gases to liquefy or solidify at low temperatures and high pressures.
Intensive Property
A property that is independent of the amount of material considered; for example, density.
Law of Constant Composition
A law that states that the elemental composition of a pure compound is always the same, regardless of its source; also called the law of definitely proportions.
Law of Definite Proportions
A law that states that the elemental composition of a pure substance is always the same, regardless of its source; also called the law of constant composition.
Liquid
Matter that has a distinct volume but no specific shape.
Mass
A measure of the amount of material in an object. It measures the resistance of an object to being moved. In SI units, mass is measured in kilograms.
Matter
Anything that occupies space and has mass. The physical material of the universe.
Metric System
A system of measurement used in science and in most countries. The meter and the gram are examples of metric units.
Mixture
A combination of two or more substances in which each substance retains its own chemical identity.
Molecule
A chemical combination of two or more atoms.
Organic Chemistry
The study of carbon-containing compounds, typically containing carbon-carbon bonds.
Physical Changes
Changes (such as phase change) that occur with no change in chemical composition.
Physical Properties
Properties that can be measured without changing the composition of a substance, for example, color and freezing point.
Precision
The closeness of agreement among several measurements of the same quantity; the reproducibility of a measurement.
Property
A characteristic that gives a sample of matter its unique identity.
Pure Substance
Matter that has fixed composition and distinct properties.
Radioactive
Processing radioactivity, the spontaneous disintegration of an unstable atomic nucleus with accompanying emission of radiation.
Redox (Oxidation-Reduction) Reaction
A reaction in which certain atoms undergo changes in oxidation states. The substance increasing in oxidation state is oxidized; the substance decreasing in oxidation state is reduced.
Scientific Law
A concise verbal statement or a mathematical equation that summarizes a wide range of observations and experiences.
Scientific Method
The general process of advancing scientific knowledge by making experimental observations and by formulating hypothesis, theories, and laws.
Significant Figures
The digits that indicate the precision by which a measurement is made; all digits of a measured quantity are significant, including the last digit, which is uncertain.
SI units
The preferred metric units for use in science.
Solid
Matter that has both a definite shape and a definite volume.
Solution
A mixture of substance that has a uniform composition; a homogeneous mixture.
States of Matter
The three forms that matter can assume: solid, liquid, and gas.
Thermochemistry
The relationship between chemical reactions and energy changes.
Thermodynamics
The study of energy and its transformation.
Valence Orbitals
Orbitals that contain the outer-shell electrons of an atom.
