Interactions of Matter Unit Test STUDY GUIDE
Use the terms from the following list to complete the sentences below.
ions
exothermic
subscript
shared
valence electron
energy
eight
group
atomic number
1. An electron that is in the outermost shell of an atom is a(n) ____________________.
2. The number of protons in an atom is its ____________________.
3. On the periodic table, atoms in the same ____________________ have the same number of valence electrons.
4. For electrons to pull away from atoms, ____________________ is needed.
5. An atom will not normally form a chemical bond if it has ____________________ valence electrons.
6. In a covalent bond, neither atom loses or gains an electron. Instead, one or more electrons are
____________________ by the atoms.
7. The number that cannot change to balance a chemical equation is the ____________________.
8. If an energy diagram shows products at a lower energy than the reactants, the diagram shows an
____________________ reaction.
Use the terms from the following list to complete the sentences below.
double-displacement
activation energy
inhibitor
subscript
9. The minimum amount of energy needed to start a reaction is called ____________________.
10. In a(n) ____________________ reaction, ions in different compounds switch places.
11. In a chemical formula, if no ____________________ is written after an element, then only one atom of the
element is present.
12. A substance that slows down or stops a chemical reaction is called a(n) ____________________.
Use the terms from the following list to complete the sentences below.
diatomic
substances
chemical bond
13. The force that holds two atoms together is called a ____________________.
14. When chemical bonds break, the atoms rearrange to form new ____________________.
15. A molecule made up of two atoms is ____________________.
Short Answer
16. Why do some atoms rarely bond?
________________________________________________________________________________________
__________________________________________________
17. How does an atom develop a charge?
________________________________________________________________________________________
__________________________________________________
18. Explain how you can use the periodic table to find the number of valence electrons for an element.
________________________________________________________________________________________
__________________________________________________
19. Explain why the noble gases do not normally form chemical bonds.
________________________________________________________________________________________
__________________________________________________
20. How would an atom of oxygen fill its outermost energy level?
________________________________________________________________________________________
___________________________________________________
21. What are the three types of chemical bonds?
________________________________________________________________________________________
______________________________________________________
Use the figure below to answer the following question.
22. Explain how many valence electrons this atom has and how many are needed to have a filled outer energy
level.
________________________________________________________________________________________
__________________________________________________
23. What is the difference between a synthesis reaction and a decomposition reaction?
________________________________________________________________________________________
_____________________________________________________
24. Name four possible signs that a chemical reaction has taken place.
________________________________________________________________________________________
______________________________________________________
25. What happens to chemical bonds during a chemical reaction?
________________________________________________________________________________________
____________________________________________________
26. Two reactants exchange elements to form two new compounds. What kind of reaction is this?
________________________________________________________________________
27. One element takes the place of another element in a compound. What kind of reaction is this?
__________________________________________________________________________
28. The following is the reaction for the explosion of nitroglycerin: What kind of reaction is this? 4C3H5(NO3)3 
12CO2 + 10H2O + 6N2 + O2
______________________________________________________________________________________________________________
29. Why does grinding a solid into a powder increase reaction rate?
____________________________________________________________________________
30. What is the law of conservation of mass?
________________________________________________________________________________________
________________________________________________________________________________________
_______________________________Matching
Match each item with the correct statement below.
a. exothermic reaction
c. endothermic reaction
b. decomposition reaction
d. single-displacement reaction
____ 31. 6CO2 + 6H2O + energy  C6H12O6 + 6O2
____ 32. H2CO3  H2O + CO2
____ 33. 2Na + Cl2  2NaCl + energy
____ 34. Zn + 2HCl  ZnCl2 + H2
Match each item with the correct statement below.
a. double-displacement reaction
c. synthesis reaction
b. decomposition reaction
d. single-displacement reaction
____
____
____
____
35.
36.
37.
38.
An element replaces another element.
Ions from two compounds exchange places.
Two substances combine to form a new compound.
A substance breaks down into new substances.
Match the labels to the equation.
____
____
____
____
____
39.
40.
41.
42.
43.
yields sign
subscript
product
coefficient
reactants
Match the labels to the corresponding parts of the graphs.
____
____
____
____
____
44.
45.
46.
47.
48.
exothermic reaction
endothermic reaction
activation energy
energy absorbed
energy released
Interactions of Matter Unit Test STUDY GUIDE
Answer Section
COMPLETION
1. ANS: valence electron
PTS: 1
DIF: 1
2. ANS: atomic number
REF: 1
PTS: 1
3. ANS: group
DIF: 1
OBJ: 2
PTS: 1
4. ANS: energy
DIF: 1
REF: 1
OBJ: 3
PTS: 1
5. ANS: eight
DIF: 1
REF: 2
OBJ: 1
PTS: 1
6. ANS: shared
DIF: 2
REF: 1
OBJ: 3
PTS: 1
7. ANS: subscript
DIF: 2
REF: 3
OBJ: 1
PTS: 1
8. ANS: exothermic
DIF: 1
REF: 2
OBJ: 3
PTS: 1
DIF: 1
9. ANS: activation energy
REF: 4
OBJ: 1 | 3
PTS: 1
DIF: 1
10. ANS: double-displacement
REF: 4
OBJ: 2
PTS: 1
11. ANS: subscript
DIF: 1
REF: 3
OBJ: 1
PTS: 1
12. ANS: inhibitor
DIF: 1
REF: 2
OBJ: 1
PTS: 1
DIF: 1
13. ANS: chemical bond
REF: 4
OBJ: 4
PTS: 1
14. ANS: substances
DIF: 1
REF: 3
OBJ: 1
DIF: 1
REF: 3
OBJ: 1
PTS: 1
OBJ: 1
15. ANS: diatomic
PTS: 1
DIF: 1
REF: 3
OBJ: 2
SHORT ANSWER
16. ANS:
They have filled the outermost energy level with 8 electrons, which make them very nonreactive.
PTS: 1
DIF: 1
17. ANS:
by gaining or losing electrons
REF: 1
OBJ: 3
PTS: 1
DIF: 1
REF: 2
OBJ: 1
18. ANS:
Atoms of elements in Groups 1 and 2 have the same number of valence electrons as their group number.
Atoms of elements in Groups 13–18 have 10 fewer valence electrons than their group number. Atoms in
Groups 3–12 do not have a general rule. The number of valence electrons in these elements is not represented
by a number in the periodic table.
PTS: 1
DIF: 2
REF: 1
OBJ: 2
19. ANS:
The atoms of the noble gases have eight valence electrons in their outermost energy level. Removing
electrons from these atoms would require a large amount of energy, so it is more difficult for noble gases to
react.
PTS: 1
DIF: 2
REF: 1
OBJ: 3
20. ANS:
An atom of oxygen has six valence electrons. In order to fill its outermost energy level, oxygen must gain two
electrons or share two electrons with other atoms.
PTS: 1
DIF: 2
21. ANS:
ionic, covalent, metallic
REF: 1
OBJ: 3
PTS: 1
DIF: 1
REF: 1
OBJ: 1
22. ANS:
The carbon atom has 4 valence electrons and needs 4 more to have a filled outer energy level.
PTS: 1
DIF: 2
REF: 3
OBJ: 1
23. ANS:
Answers may vary. Sample answer: In a synthesis reaction, two or more substances combine to form a single
compound. A decomposition reaction is the reverse of a synthesis reaction because a single compound breaks
down to form two or more simpler substances.
PTS: 1
DIF: 2
REF: 3
OBJ: 1
24. ANS:
gas formation, solid formation, energy change, and color change
PTS: 1
DIF: 1
25. ANS:
They break, and new bonds are formed.
REF: 1
OBJ: 2
PTS: 1
DIF: 2
26. ANS:
double-displacement
REF: 1
OBJ: 3
PTS: 1
DIF: 1
27. ANS:
single-displacement
REF: 3
OBJ: 2
PTS: 1
28. ANS:
decomposition
REF: 3
OBJ: 2
DIF: 1
PTS: 1
DIF: 2
REF: 3
OBJ: 2
29. ANS:
The powdered form exposes more particles of the reactant, allowing more collisions with another reactant.
PTS: 1
DIF: 1
REF: 4
OBJ: 4
30. ANS:
Answers may vary. Sample answer: The laws of conservation of mass and conservation of energy are similar
in that each states that something is neither created nor destroyed in a chemical reaction—energy can change
form or be transferred, and no atoms are gained or lost. A chemical equation is balanced in respect to both
mass and energy.
PTS: 1
DIF: 2
REF: 2
OBJ: 3
MATCHING
31. ANS:
OBJ:
32. ANS:
OBJ:
33. ANS:
OBJ:
34. ANS:
OBJ:
C
1
B
1|2
A
1
D
1|2
PTS: 1
DIF: 1
REF: 4
PTS: 1
DIF: 1
REF: 3
PTS: 1
DIF: 1
REF: 4
PTS: 1
DIF: 1
REF: 3
35. ANS:
OBJ:
36. ANS:
OBJ:
37. ANS:
OBJ:
38. ANS:
D
1
A
1
C
1
B
PTS: 1
DIF: 1
REF: 3
PTS: 1
DIF: 1
REF: 3
PTS: 1
DIF: 1
REF: 3
PTS: 1
DIF: 1
REF: 3
OBJ: 1
39. ANS:
OBJ:
40. ANS:
OBJ:
41. ANS:
OBJ:
42. ANS:
OBJ:
43. ANS:
OBJ:
C
1
B
1
D
1
A
1
E
1
PTS: 1
DIF: 1
REF: 2
PTS: 1
DIF: 1
REF: 2
PTS: 1
DIF: 1
REF: 2
PTS: 1
DIF: 1
REF: 2
PTS: 1
DIF: 1
REF: 2
44. ANS:
OBJ:
45. ANS:
OBJ:
46. ANS:
OBJ:
47. ANS:
OBJ:
48. ANS:
OBJ:
D
4
E
4
A
4
B
4
C
4
PTS: 1
DIF: 1
REF: 4
PTS: 1
DIF: 1
REF: 4
PTS: 1
DIF: 1
REF: 4
PTS: 1
DIF: 1
REF: 4
PTS: 1
DIF: 1
REF: 4