Classifying Materials 19 Questions and Exercises K C
Key Concepts Rewrite the following sentences in your copybook and fill in the blanks. 1. A pure substance is one that is made from ____________________ type of particle. 2. A mixture is made of ____________________ or more different kinds of ____________________ that are ____________________ together.
3. An element is a ____________________ substance that ____________________ be broken down into ____________________ substances by ____________________ means.
4. A compound is a ____________________ substance made from two or more ____________________ which are ____________________ combined.
5. A ____________________ change is one in which no new substances are made. 6. A ____________________ change causes new substances to form.
K U
Knowledge and Understanding 1. What is the difference between a mixture and a compound? Explain by referring to the
atomic nature of matter.
2. Classify the following changes as physical changes or chemical reactions: (a) Ice melting
(g) Iron rusting
(b) Making iron sulfide (c) Adding salt to sand
(d) Dissolving sugar in water (e) Melting lead (f) Burning paper
(h) Evaporating alcohol (i) Milk turning sour
(j) Making ice cubes in a freezer (k) Chopping wood (l) Digesting food
3. How does the atomic nature of matter explain physical changes and chemical reactions? 4. Draw a table similar to the one provided below. Arrange the substances (a) – (q) under the headings, Element, Compound and Mixture in your table.
