SECTION
ELEMENTS COMBINE TO FORM COMPOUNDS.
2.1 Reading Study Guide A
BIG IDEA The
properties of compounds depend on their atoms and chemical bonds.
KEY CONCEPT
Elements combine to form compounds.
Vocabulary
Review
1.
Fill in the concept map for atoms.
ATOMS
of each element
have symbols listed
in the
may combine
with different atoms
to form
Take Notes
I.
Compounds have different properties from the elements that make
them. (p. 41)
2.
Complete the following sentences.
a. A
compound is a substance made of atoms of two or more different
_____________________.
b. In
a compound, atoms are held together by chemical ____________.
c. A
compound’s properties are often very ____________ from those of
the elements that make it up.
Copyright © by McDougal Littell, a division of Houghton Mifflin Company
CHAPTER 2
Chemical Bonds and Compounds
chemical formula symbols that show which atoms and the ratio of these atoms
needed to make a certain compound
subscript a number written to the right of a chemical symbol and a little below it
72 CHEMICAL INTERACTIONS, CHAPTER 2, READING STUDY GUIDE A
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II. Atoms combine in predictable numbers. (p. 42)
3.
Complete the following sentences.
a.
______________________ shows which atoms and the ratios of these atoms
needed to make a chemical formula.
b. A
______________________ is a number written to the right of a
chemical symbol and a little below it.
Circle the picture that shows objects in a 3:4 ratio. Draw a square around the
picture that shows objects in a 1:1 ratio.
CHAPTER 2
Chemical Bonds and Compounds
4.
A. Chemical Formulas (p. 43)
Copyright © by McDougal Littell, a division of Houghton Mifflin Company
5.
The table below lists several chemical formulas. For each formula, write how
many atoms of each element combine to make that compound. The first row has
been done for you.
Molecule
H2O
Atoms Making It Up
2 hydrogen, 1 oxygen
CO2
H2O2
C3H8
B. Same Elements, Different Compounds (p. 44)
6.
Write the chemical formulas for two compounds that have the same elements
in different ratios.
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