# Properties and states of matter

Flashcard maker : Clarence Louder
 Significant Figure
 Measured values which include all known digits plus one estimated digit.
 Density
 An intensive physical property of matter defined as the amount of mass per unit volume.
 Solution
 Another term for homogeneous mixtures.
 Concentration
 A measure of how much solute (usually solid) is dissolved in a specific amount of solvent (usually liquid) or solution. It is usually expressed in units of weight percent (like 20% salt solution).
 Calibration Curve
 A straight-line relationship between density of a solution and the concentration of the solute. It is used to find the concentration of solute in an unknown solution.
 Pipetting
 A method of delivering an accurate and precise volume of liquid to another container.
 Percent Error
 The determination of the error in experimentation as a percentage of the accepted value.
 Best-fit line
 Instead of connecting-the-dots with data points in a graph, a line which shows about as many data points above the line as below is drawn.
 Weight percent
 Units used to express concentration of a solution which corresponds to the number of grams of solute that are present in 100 grams of solution. 20g of sodium chloride in 80 g of water creates a 20 % solution.
 Melting point
 A characteristic physical property when a solid and a its liquid are in equilibrium at the temperature at which a crystalline solid becomes a liquid.
 Boiling Point
 A physical property describing the temperature at which the vapor pressure of a liquid equals the external or atmospheric pressure.
 Freezing Point
 A physical property describing the temperature at which a liquid changes into a crystaline solid.
 Surface Tension
 A net attractive force that tends to pull adjacent surface molecules inward, thus decreasing the surface of a liquid to the smallest possible size.
 Chemical Property
 The ability of a substance to combine with or change into one or more other substances
 Chemical Change
 A process that involves one or more substances changing into new substances.
 Physical Property
 A characteristic that can be observed or measured without changing the sample’s composition.
 Physiscal Change
 A change which alters a substance without changing its composition.
 Extensive Property
 Physical properties which are dependent on the amount of the substance present..
 Intensive Property
 Physical properties which are independent of the amount of the substance present.
 Kinetic Molecular Theory
 Describes how close together the molecules are in a solid, liquid, and a gas , their relative motion, and the attractive forces between the molecules.
 Temperature
 The average kinetic energy of the molecules in a substance.
 States of Matter
 The different physical forms substances can have on Earth.
 Phase Change
 A transition of matter from one state of matter to another.
 Vapor
 The gaseous state of a substance that is a solid or a liquid at room temperature.
 Gas
 A form of matter that flows to conform to the shape of its container and fills the entire volume of its container. The substance exists in the gaseeous state at room temperature.
 Law of Conservation of Mass
 Matter is neither created nor destroyed during a chemical reaction. In other words, the mass of the reactants is equal to the mass of the products.
 Mixture
 A combination of two or more pure substances in which each pure substance retains its individual chemical properties and whose composition is variable.
 Element
 A pure substance that cannot be separated into simpler substances by physical or chemical means.
 Compound
 A pure substance made up of two or more different elements that are combined chemically.
 Heterogeneous
 A mixture that does not blend smoothly throughout and in which the individual substances remain distinct.
 Homogeneous
 A mixture that has constant composition throughout; it always has a single phase.
 Pure Substance
 Matter with a uniform and unchanging composition.
 Chromatography
 A technique that separates the components of a mixture(mobile phase) based on the ability of each component to travel or be drawn across the surface of another material (stationary phase).
 Distillation
 A separation technique used on homogeneous mixtures that is based on differences in boiling points of the substances involved.
 Filtration
 A technique which uses a porous barrier to separate solids from liquids.
 Sublimation
 Process during which a solid changes to vapor without melting. This can be used as a separation technique if in a mixture of more than one solid, one of the solids can go through this type of change.
 Condensation
 The process by which a gas or a vapor becomes a liquid.
 Evaporation
 Vaporization occuring at the surface of a liquid.
 Phase Diagram
 A graph of pressure versus temperature that shows in which phase a substance exists under different conditions of temperature and pressure
 Exothermic
 A type of reaction which occurs when more energy is relased as heat or light when bonds of the product are formed than the energy required to break the bonds of the reactants.
 Endothermic
 A type of reaction which occurs when a greater amount of energy is required to break the existing bonds in the reactants than is released when the new bonds form in the products. Energy is absorbed.
 Immiscible
 Describes two liquids that can be mixed together but separate shortly after you cease mixing them.
 Solvation
 When solute particles are surrounded by solvent particles to form a solution (dissolving).
 Solute
 One or more substances dissolved in a solvent or solution (usually solids)
 Solvent
 ubstance that dissolves the solute to form a solution; the most plentiful substance in the solution.
 Law of Definite Proportions
 States that a compound is always composed of the same elements in the same proportion by mass, no matter how large or small the sample.
 Electrolysis
 The process that uses electricity to separate a compound into its individual elements.
 Independent Variable
 In an experiment, it is the variable which is manipulated by the experimenter.
 Dependent Variable
 In an experiment, it is the variable which is not known prior to the experiment, but is measured and changes as the independent variable changes.
 Control Group
 In an experiment, the standard that is used for comparison. It does not get the independent variable.
 Experimental Group
 In an experiment, the test groups which have the independent variable applied.
 Constants
 The variables which remain the same between the experimental and control groups.
 Hypothesis
 A tentative, testable statement or prediction about what has been observed. An educated guess of the results of an experiment.