wayground logo

Free Printable Worksheets

Font size

S
M
L
XL
Worksheets

Unit 2 Test - Study Guide - Lewis

Total questions: 97

Worksheet time: 2hrs 35mins

Name
Class
Date
1.

What is a chemical reaction?

a)

A chemical reaction is a process that leads to the formation of new elements.

b)

A chemical reaction is a process that leads to the destruction of chemical substances.

c)

A chemical reaction is a process that leads to the separation of chemical substances.

d)

A chemical reaction is a process that leads to the transformation of one set of chemical substances to another.

2.

What is the purpose of balancing chemical equations?

a)

To make the equation look more balanced.

b)

To make the equation easier to understand.

c)

To ensure the law of conservation of mass is obeyed.

d)

To satisfy the chemist's aesthetic sense.

3.

How do you count atoms in a chemical equation?

a)

By dividing the equation into smaller parts and counting the atoms in each part

b)

By using the atomic mass of each element in the equation

c)

By counting the number of elements in the equation

d)

By balancing the equation and using coefficients to determine the number of atoms.

4.

State the law of conservation of mass.

a)

Mass cannot be created or destroyed

b)

Mass can be both created and destroyed

c)

Mass can be destroyed but not created

d)

Mass can be created but not destroyed

5.

What are the four main types of chemical reactions?

a)

synthesis, decomposition, single displacement, and double displacement

b)

ionization, dissociation, precipitation, and neutralization

c)

evaporation, condensation, sublimation, and deposition

d)

oxidation, reduction, combustion, and neutralization

6.

In a chemical equation, what does the arrow represent?

a)

=>

b)

->

c)

<

d)

<=

7.

What is the difference between reactants and products in a chemical equation?

a)

Reactants are the substances formed as a result of a chemical reaction, while products are the substances present at the beginning of the reaction.

b)

Reactants and products are interchangeable terms in a chemical equation.

c)

Reactants are the substances present at the beginning of a chemical reaction, while products are the substances formed as a result of the reaction.

d)

Reactants and products are the same thing in a chemical equation.

8.

What happens to the mass of reactants and products in a chemical reaction?

a)

The mass of reactants increases.

b)

The mass of reactants decreases.

c)

The mass of reactants and products remains constant.

d)

The mass of products increases.

9.

What is a synthesis reaction?

a)

A synthesis reaction is a type of chemical reaction in which two or more substances combine to form a substance with the same properties as the original substances.

b)

A synthesis reaction is a type of chemical reaction in which two or more substances break down into simpler substances.

c)

A synthesis reaction is a type of chemical reaction in which two or more complex substances combine to form a simpler substance.

d)

A synthesis reaction is a type of chemical reaction in which two or more simple substances combine to form a more complex substance.

10.

Give an example of a combustion reaction.

a)

Burning of carbon dioxide (CO2)

b)

Burning of methane (CH4)

c)

Burning of oxygen (O2)

d)

Burning of water (H2O)

11.

What is the chemical formula for water?

a)

H2O

b)

CO2

c)

CH4

d)

O2

12.

How can you determine the number of atoms in a chemical equation?

a)

By dividing the equation into smaller parts and counting the atoms in each part

b)

By using the atomic mass of each element in the equation

c)

By counting the number of elements in the equation

d)

By balancing the equation and using coefficients to determine the number of atoms

13.

What symbol is used to represent a chemical reaction?

a)

=>

b)

->

c)

<

d)

<=

14.

What is the chemical symbol for gold?

a)

Au

b)

Ag

c)

Fe

d)

Cu

15.

What is the purpose of the arrow in a chemical equation?

a)

To indicate the direction of the reaction

b)

To separate the reactants and products

c)

To show the formation of a new substance

d)

To balance the equation

16.

What happens to the mass of reactants and products in a chemical reaction?

a)

The mass of reactants increases.

b)

The mass of reactants decreases.

c)

The mass of reactants and products remains constant.

d)

The mass of products increases.

17.

What is a balanced chemical equation?

a)

An equation that has an equal number of atoms of each element on both sides.

b)

An equation that has more reactants than products.

c)

An equation that has more products than reactants.

d)

An equation that has different elements on both sides.

18.

What is the purpose of balancing chemical equations?

a)

To make the equation look more balanced.

b)

To make the equation easier to understand.

c)

To ensure the law of conservation of mass is obeyed.

d)

To satisfy the chemist's aesthetic sense.

19.

What is an exothermic reaction?

a)

An exothermic reaction is a chemical reaction that releases energy in the form of heat or light.

b)

An exothermic reaction is a chemical reaction that absorbs energy from the surroundings.

c)

An exothermic reaction is a chemical reaction that does not release or absorb energy.

d)

An exothermic reaction is a chemical reaction that only releases energy in the form of light.

20.
Which of the following is a sign that a chemical reaction has occurred?
a)
change in shape
b)
melting
c)
formation of a gas
d)
dissolving
21.
Is burning wood a chemical or physical change?
a)
chemical
b)
physical
22.
A change in the size, shape, or state of matter.
a)
chemical change
b)
physical change
c)
chemical reaction
d)
electron change
23.
Which of the following is NOT an example of a physical change?
a)
crumpled paper
b)
pencil sharpening
c)
shrunken clothing
d)
sour milk
24.
Four students performed four different investigations by combining different substances. Their results are shown in the table provided. In which experiment are new substances being formed?
a)
Experiment 1
b)
Experiment 2
c)
Experiment 3
d)
Experiment 4
25.
A clear liquid from a flask is poured into another clear liquid in a beaker. Which of the following results of this procedure would indicate a new substance was formed?
a)
The level of the substance in the beaker is higher after the other liquid is added.
b)
A yellow solid forms and then settles to the bottom of the beaker.
c)
Small white crystals are left behind in the flask that held the first liquid.
26.
Which of the following is an example that includes evidence of a chemical reaction?
a)
A sample of zinc is placed in water and it settles to the bottom
b)
A solid block of ice is heated and it completely melts into a liquid. 
c)
Sugar that is burned gives off an odor and turns brown and then black.
d)
A tomato is placed into a blender and chopped up into smaller pieces.
27.
Evidence of a chemical reactions is anything that shows - 
a)
a new substance has formed
b)
a solid dissolved in a liquid
c)
interaction between 2 gases
d)
a change in the state of matter
28.
If you break a piece of glass, the shape of the glass changes, but the properties in the fragments remain the same. Which of the following has occurred?
a)
A chemical change.
b)
A temperature change.
c)
A phase change.
d)
A physical change.
29.
A student observes some sugar as it is heated and burns. The student concludes that a chemical reaction has occurred. Which of the following observations about the burning sugar provides evidence of a chemical reaction?
a)
Heat is added to the sugar crystals.
b)
The sugar melts and becomes a liquid.
c)
Gas is produced as the sugar turns black.
d)
No evidence of chemical reaction is present.
30.

What does the Law of Conservation of Mass say? It says,


"During a chemical reaction, mass is neither _______ or destroyed."

a)

burned

b)

created

c)

melted

31.

The substances that go into a reaction are called the _______.

a)

products

b)

reactants

32.

So, the Law of Conservation of Mass would tell us that the mass of all the REACTANTS must __________ the mass of all PRODUCTS in a chemical reaction.

a)

equal

b)

be greater than

c)

be less than

33.

What coefficient should be used to make the following equation balanced?

N2+O2--> __?__NO

a)

1

b)

2

c)

3

d)

4

34.

According to the Law of Conservation of Mass (Matter), Matter cannot be ​ (a)   or ​ (b)   , it can only be ​ (c)   . This means however many atoms of an element we have before a reaction must be ​ (d)   to the number after a reaction.

Choose from the below words
created
destroyed
changed
equal
35.
What is the little number after an element in a chemical equation called.
Example: H2
a)

Coefficient 

b)

Subscript

c)

Atom

d)

Equation

36.
Which of the following equations are correctly balanced?
a)

12CO2 +H2O --> C6H12O6 + O2

b)

CO2 + 9H2O --> C6H12O6 + O2

c)

CO2 + H2O --> 3C6H12O6 + O2

d)

6CO2 + 6H2O --> C6H12O6 + 6O2

37.
Is the following equation balanced?
4Fe + 3O2 --> 2Fe2O3
a)
yes
b)
no
38.
What is the right part of a chemical equation called...
2H2 + O2 --> 2H2O
a)
Reactants
b)
Products 
c)
Yields 
d)
Chemical Equation 
39.
How many elements are in C6H12O6?
a)
1
b)
2
c)
3
d)
4
40.
What is the number before a chemical formula called?
Ex: 2H2 + O2 --> 2H2O
a)
Coefficient
b)
Subscript
c)
Atom
d)
Equation
41.
How many atoms are in the neurotransmitter serotonin? The formula for serotonin is C10H12N2O
a)
10
b)
20
c)
25
d)
23
42.
What information could a student determine from only the chemical formula of a protein?
a)
The color of the protein
b)
The number of molecules in each sequence of the protein
c)
The physical arrangement of atoms in the structure of the protein
d)
The number of atoms of each element in the protein
43.
Is the following equation balanced?
2C2H2 + 5O2 --> 4CO2 + 2H2O
a)
yes
b)
no
44.
How many HCl molecules do you need to balance this equation? 
Mg +  __HCl --->  MgCl2 + H2
a)
1
b)
2
c)
3
d)
4
45.

Determined whether the following equation is balanced or unbalanced. Ag + O2 ---> 2Ag2O

a)

Balanced

b)

Unbalanced

46.

Determine whether the following equations is balanced or unbalanced. H4 + O2 ---> 2H2O

a)

Balanced

b)

Unbalanced

47.

Determine whether the following equation is balanced or unbalanced. 4P +5O2 ---> 2P2O5

a)

Balanced

b)

Unbalanced

48.

Determine whether the following equation is balanced or unbalanced. H2 + Br2 ---> 2HBr

a)

Balanced

b)

Unbalanced

49.

Determine whether the following equation is balanced or unbalanced. 2Fe + 3Cl2 ---> FeCl3

a)

Balanced

b)

Unbalanced

50.

Determine whether the following equations is balanced or unbalanced. S8 + O2 ---> 8SO3

a)

Balanced

b)

Unbalanced

51.

In order for an equation to be balanced, there must be ...

a)

an equal amount of atoms on both sides

b)

a greater mass on the product side

c)

a greater mass on the reactant side

d)

elements with the same atomic # on both sides

52.

Which coefficients would balance this chemical equation? _Fe2O3 ---> _Fe + _O2

a)

2,1,2

b)

2,4,3

c)

1,1,1

d)

1,3,2

53.

Which coefficients would balance this chemical equation? _K + _Cl2 ---> _KCl

a)

1,1,1

b)

1,2,2

c)

1,1,2

d)

2,1,2

54.

Which of the following equations is balanced?

a)

P4 + 3O2 ---> 2P2O3

b)

N4 + 3F2 ---> 2NF3

c)

2LiF + Br2 ---> 2LiBr + F4

55.
How many Hydrogen are in 4H2O?
a)
6
b)
8
c)
2
d)
4
56.
How many Oxygen are in H2O?
a)
1
b)
2
c)
0
d)
4
57.
How many Magnesium are in 10MgCl2?
a)
10
b)
5
c)
20
58.
How many O's are in Al₂(SO₄)₃
a)
4
b)
12
c)
7
d)
24
59.
Number of H in 3(NH₄)₂CrO₄
a)
4
b)
2
c)
8
d)
24
60.
How many atoms are there TOTAL in:
H2SO4
a)
6
b)
5
c)
7
d)
3
61.
How many Sodium (Na) are in 6NaCl?
a)
1
b)
12
c)
6
62.
A subscript is the small number below a(n) ________ that tells the number of _______ of that element.
a)
element symbol; atoms
b)
atom; element symbol
c)
subscript; protons
d)
compound; elements
63.
How many O's are in Al₂(SO₄)₃
a)
4
b)
12
c)
7
d)
24
64.

What elements are represented in this chemical formula? Fe2O3Fe_2O_3  

a)

Iron, Oxygen

b)

Francium, Europium, Oxygen

c)

Ferrium, Oxygen

d)

Berylium, Oxygen

65.

What is the total number of atoms in this formula? H2O2H_2O_2  

a)

2

b)

4

c)

3

66.

How many more atoms of Oxygen than than Magnesium are in this formula? (subtraction) MgSO4MgSO_4  

a)

4

b)

3

c)

2

d)

6

67.

Is this an element or a compound? CaSO4CaSO_4  

a)

Element

b)

Compound

68.

Which chemical formula correctly displays 1 atom of nickel and 2 atoms of Fluorine?

a)

niF2

b)

NIF2

c)

Ni1F2

d)

NiF2

69.

What is the total number of atoms in this chemical formula? C8H3NaBr12C_8H_3NaBr_{12}  

a)

18

b)

12

c)

25

d)

24

70.

2 CH2CO3OH

Number of C: ​ (a)  

Number of H: ​ (b)  

Number of O: ​ (c)  

Choose from the below words
4
6
8
2
3
1
5
7
9
10
71.

Match the element to the number of atoms it has.

2 Al(C2H3O4)2

a)

aluminum

1.

2

b)

carbon

2.

8

c)

hydrogen

3.

12

d)

oxygen

4.

16

72.

Coefficients in chemical formulas...

a)

are found at the beginning of a formula and multiply just the first atom

b)

are found at the end of a formula and multiply EVERYTHING!

c)

are found at the end of a formula and multiply only elements inside the parentheses.

d)

are found at the beginning of a formula and multiply EVERYTHING!

73.

How many atoms of Calcium are in this equation?

H3O5CaCl7

a)

3

b)

5

c)

1

d)

7

74.

How many atoms of Carbon are in this equation?


HʒC5O4

a)

3

b)

1

c)

5

d)

4

75.

How many total atoms in the following equation?

ClN6Fe2

a)

6

b)

8

c)

10

d)

9

76.

Identify the Coefficient.

3BeH5Si8

a)

5

b)

3

c)

1

d)

8

77.

Identify the subscripts.

4Fe5K2

a)

4

b)

5

c)

2

d)

1

78.

How many atoms of Iron in the following equation?

2HFe5Cl

a)

1

b)

10

c)

5

d)

20

79.

How many total atoms in the following equation?

3He2Ag5

a)

2

b)

21

c)

24

d)

5

80.

How many atoms of Hydrogen are in this equation?

5Cl2H5

a)

10

b)

2

c)

5

d)

25

81.

How many atoms of Iron in the following equation?

C2HAu5

a)

2

b)

0

c)

9

d)

7

82.

How many total atoms in the following equation?

2(H2)3

a)

2

b)

6

c)

7

d)

12

83.

Lighting a Match

a)

Physical Change

b)

Chemical Change

84.

Melting Ice Cream

a)

Physical Change

b)

Chemical Change

85.

Popping Popcorn

a)

Physical Change

b)

Chemical Change

86.

Blowing up a balloon

a)

Physical Change

b)

Chemical Change

87.

Rotting banana

a)

Physical Change

b)

Chemical Change

88.

Cooking Pancakes

a)

Physical Change

b)

Chemical Change

89.

Crumpling Paper

a)

Physical Change

b)

Chemical Change

90.

Slicing Bread

a)

Physical Change

b)

Chemical Change

91.

Rusting Nail

a)

Physical Change

b)

Chemical Change

92.

Cutting a banana

a)

Physical Change

b)

Chemical Change

93.

Dying your hair blonde

a)

Physical Change

b)

Chemical Change

94.

Evaporating Water

a)

Physical Change

b)

Chemical Change

95.

Burnt toast

a)

Physical Change

b)

Chemical Change

96.

Adding baking soda to vinegar

a)

Physical Change

b)

Chemical Change

97.

Bending a metal rod

a)

Physical Change

b)

Chemical Change

Similar Resources on Wayground

Earth Space Science Review

100 questions

Earth Space Science Review

quiz

Worksheet

•

6th - 8th Grade

1st Semester exam 25 review part 1

92 questions

1st Semester exam 25 review part 1

quiz

Worksheet

•

8th Grade

Sains darjah 2

100 questions

Sains darjah 2

quiz

Worksheet

•

1st - 10th Grade

Earth Science EOC Review

96 questions

Earth Science EOC Review

quiz

Worksheet

•

6th - 8th Grade

PMA 2 Review

100 questions

PMA 2 Review

quiz

Worksheet

•

8th Grade

Heat Pump Prep Test

100 questions

Heat Pump Prep Test

quiz

Worksheet

•

1st Grade - Professio...

8th Grade STAAR Vocab Science (3)

94 questions

8th Grade STAAR Vocab Science (3)

quiz

Worksheet

•

6th - 8th Grade

8th Grade Science STAAR Review 2022

100 questions

8th Grade Science STAAR Review 2022

quiz

Worksheet

•

6th - 8th Grade