Chapter Overview During this unit, students review and extend their understanding of the physical and chemical properties of matter, as manifested in elements, compounds, and mixtures. Main Ideas Analysis of the relationships between physical and chemical changes and properties is essential to understanding the nature of matter. *How are the properties of matter distinguished? *Why is the investigation and analysis of matter essential to the study of chemistry? *In what ways are properties used to classify matter? *How are changes in matter analyzed? Misconceptions ***Students may think mass and weight are the same, rather than understanding that mass is the amount of matter in an object or substance and weight is a measure of the force of gravity on that matter or substance. ***Students may think a single observable change in properties, such as heat being given off or absorbed, is enough to indicate a chemical change. ***Students may think objects with larger volumes always have more mass. ***Students may think air and other gases do not have mass or weight. ***Students may not understand mass-volume relationships (density) as well as measuring and calculating density. ***Students may not understand that a sample of matter is either a pure substance or a mixture of pure substances. Vocabulary Matter – anything that has mass
and takes up space Structure – arrangement of bonds
between atoms in a molecule Pure Substance – substances that are made of only one type of atom or only one type of molecule Element – substance that cannot
be broken down into simpler substances by chemical means Molecule – a group of atoms
bonded together, representing the smallest fundamental unit of a chemical
compound that can take part in a chemical reaction Compound – a substance formed
when two or more chemical elements are chemically bonded together Mixture – substance made of two
or more different substances that are mixed but are not chemically combined Solution – mixture with two or
more substances Decant – separation of mixtures
by removing a layer of liquid Distillation – separating the
parts of a liquid by boiling it and then condensing the vapor that results Filtration – separation of solids
from fluids by adding a medium through which only the fluid can pass Physical Property – a
characteristic of a pure substance that can be observed or measured without
changing the substance’s chemical identity Extensive Property – a physical
property that depends on the amount of matter present Intensive Property – a physical
property that does not depend on the amount of the substance present Compressibility – the measure of
how much a given volume of matter decreases when placed under pressure Density – the ration between mass
and volume (d=m/v) Ductility – physical property of
a material associated with the ability to be drawn into a wire Elasticity – physical property of
a material where the material returns to its original shape after being
deformed Malleability – physical property
of a material associated with the ability to be hammered thin into a sheet Viscosity – a liquid’s resistance
to flow Volume – amount of space occupied
by a substance Physical Change – a change that
alters a substance without changing its chemical composition or its identity Evaporation – process of a
substance in liquid state changing to a gaseous state Sublimation – substance changes
from a solid to a gas without passing through the liquid phase Vaporization – substance changes
from the liquid to gaseous state Chemical Property – a
characteristic of a pure substance that describes how it interacts with other
substances Chemical Change – a change in the
chemical composition and the identity of a substance Reactivity – tendency of a
substance to undergo chemical changes Solubility – degree to which a
substance dissolves in a solvent to make a solution Notes Other Valuable Resources |
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