Page 143 - Science Course 2 (Book 1)

Mo5-L2: Key Concept Check

Direction: On the line before each statement, write T if the statement is true or F if the statement is false.

1. liquid or gas at room temperature 5. poor conductor of electricity
2. metallic luster 6. very high boiling point
3. low melting point 7. chemically unstable
4. always solid at room temperature 8. made up of molecules

Direction: On the line before each description, write S if it is held together by a single bond, D if it is held
together by a double bond, and T if it is held together by a triple covalent bond.

9. molecular nitrogen (N ) 10. molecular hydrogen (H ) 11. carbon dioxide (CO )
2 2 2

Mo5-L2: Lesson Review Quiz (True or False)

Direction: Put a check mark on the line before each property that is typical of a covalent compound.

1. A compound can have different chemical and physical properties than those of the elements it is
made from.

2. A chemical formula shows the total number of atoms in a sample of a compound.

3. A molecule is a group of atoms held together by covalent bonding that acts as an
independent unit.

4. A polar molecule is one that has equal electron attraction between atoms.

Mo5-L2: Lesson Review Quiz (Completion)

Direction: On each line, write the term that correctly completes each sentence.

5. A(n) can have different chemical and physical properties than those of the
elements it is made from.
6. A(n) is a group of chemical symbols and numbers that represent the
elements and the numbers of atoms of each element that make up a compound.
7. A(n) is a group of atoms held together by covalent bonding that acts as an
independent unit.
8. A polar molecule has a slight charge near the atom that attracts the
shared electron more strongly.

Short Anwser
Direction: Respond to each statement on the lines provided.
9. List the types and numbers of atoms represented in the chemical formula for methane, CH .
4

10. Describe how polar and nonpolar liquids can be used to dissolve different substances.

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