Properties, Changes, and Classification of Matter

Gap-Fill Exercise
Content © 2006 Melanie Cecere; Authors of Activity: Melanie Cecere & Tami Maloney; All rights reserved. No commercial, for-profit use of this material is allowed. E-mail comments and questions to Tami Maloney.

Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!
Matter is classified by its and properties. Properties are used to distinguish between different substances and to separate them. There are two general types of properties. A physical is a characteristic that can be observed or measured without changing the identity of the substance. It describes the substance itself rather than its behavior (melting point, boiling point). A physical is a change in a substance that does not involve a change in the identity of the substance (grinding, cutting, melting, boiling). Changes of state are changes from one state to another. The three normal states of matter are ( volume and shape; particles vibrate about a fixed point), (definite , indefinite shape; takes the shape of the container because particles can around each other); and ( volume, shape; fills and takes the shape of container). properties depend on the amount of matter present (volume, mass, amount of energy). properties don't (melting point, boiling point, density, ability to conduct heat or electricity, etc.).

properties relate to a substance's ability to undergo changes that transform it into different substances (how it behaves with other substances). is the tendency of an element to enter into a chemical reaction. A chemical change (aka ) is a change in which one or more substances are converted into different substances (rusting, souring milk, tarnishing silver). After a change, the original substances are no longer present. For example, burning sugar turns into carbon and water. The substance(s) that react are called . The substances that are formed by the chemical change are called . There are many ways to tell a reaction has taken place. For example, an , heat or given off, production of electricity or gas (not ), and formation of a (insoluble solid) are all signs of a chemical reaction. Energy is always involved in a physical or chemical change. An change releases energy (crystallization, freezing, explosions, burning). An change absorbs energy (melting, evaporation, electrolysis).

Matter exists as either a pure substance or a . are a blend of two or more kinds of matter, each retaining their own identity and properties. There are two types of mixtures. mixtures are uniform in composition. The same proportions of components exist throughout. All solutions are mixtures (ex: salt water). mixtures are not uniform throughout (ex: clay and water). You can separate mixtures in many different ways, including filtration, , decanting, centrifugation, and paper . have a fixed composition and differ from mixtures in many ways. For example, every sample of a given substance has exactly the same characteristic and properties. Every sample of a given pure substance has exactly the same . Compounds can be decomposed into simpler or with a change. Elements and compounds are .

Elements are that cannot be decomposed by changes. They are the "building blocks" of matter. Each element has characteristic properties. They are organized into groups based on similar properties on the periodic table of the elements. Most elements' are related to their English names. Nine relate to their names (Cu, Au, Fe, Pb, Hg, K, Ag, Na, Sn) and 2 to their names (Sb, W). In writing symbols for elements, you always capitalize the , and NEVER the (eg, Co, not CO)
The has columns and rows. The are called Groups or Families. There are groups, and each group has similar properties, such as metals or nonmetals. The rows are called Periods or . There are periods. The physical and chemical properties of the elements change as you go a period. The series fit after #57, and the series fit after #89. They're put at the bottom to keep the chart from being so wide.
There are four broad divisions of elements on the periodic table:
are good conductors of heat and electricity. They are (can be hammered into thin sheets) and (can be drawn into wire because they have high tensile strength-ability to resist breaking when pulled). Most are . W (tungsten) has the highest point. Hg (mercury) is a at room temperature. Ga (gallium) will melt in your hand. Group I metals are so you can cut them with a knife. Cr (chromium) is very hard. Most metals have a silver or grayish white luster (except Cu and Ag).
Nonmetals are , solids, or liquids. They are conductors of electricity. are elements that have some characteristics of metals and some of nonmetals. They border the stair step line that separates metals from nonmetals. All are . They are not as malleable as metals but not as as nonmetals. They are of electricity. They are used in desktop computers, calculators, digital watches, and radios.
are unreactive. They are gases at room temperature. Before 1962, they were not known. Their low reactivity sets them apart from other elements. Ne, Ar, Kr, and Xe are used in lighting. He is used in balloons. He, Ne and Ar are (they do NOT react).