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Chemical Reactions

Total questions: 128

Worksheet time: 2hrs 10mins

Name
Class
Date
1.

Everything is made of_____________________.

a)

chemicals

b)

science

c)

sodium chloride

d)

helium

2.

Chemicals can react to form_______________________.

a)

new chemicals

b)

more atoms

c)
nothing
d)

the same chemicals

3.

What happened when Bill ran electricity through the water molecules?

a)

They made bigger water molecules

b)

Water split into Hydrogen and Oxygen gas

c)

It boiled and became water vapor

d)

It became carbon dioxide gas

4.

What happened when the steel wool reacted with the oxygen in the air?

a)

The steel wool glowed and gave off energy

b)

The steel wool burned and absorbed energy

c)

The steel wool reacted with Nitrogen in the air

d)

The steel wool boiled and became a gas

5.

In the steel wool reaction, energy____________________.

a)

was given off

b)

was destroyed

c)

was absorbed

d)

did not change

6.

Fire is a​ (a)   that happens when chemicals react with ​ (b)   in the air.​ ​

Choose from the below words
Chemical Reaction
oxygen
nitrogen
physical change
carbon dioxide
7.

What happened when the Sodium(Na) was put in water?

a)

It glowed and gave off energy

b)

It dissolved

c)

Nothing happened

d)

It glowed and absorbed energy

8.

Sodium and Chlorine when separate are dangerous. But when they are ​ (a)   ​ they form ​ (b)   which is also called ​ (c)   .

Choose from the below words
bonded
sodium chloride
salt
separated
sugar
energy
9.

When a chemical reaction takes in more energy than it gives off it becomes _______________.

a)

colder

b)

hotter

c)

bigger

d)

smaller

10.

There are only_________ naturally occurring elements in the world.

a)

92

b)

300

c)

2

d)

103

11.

Tiny pieces of matter that everything is made of

a)

model

b)

atoms

c)

substances

12.

An object, diagram, or computer program that helps us understand something by making it simpler or easier to see

a)

molecule

b)

property

c)

model

13.

Something that can be observed about a substance, such as color, smell, or boiling point

a)

property

b)

reactant

c)

molecule

14.

A process in which atoms rearrange to form new substances.

a)

extended structure

b)

boiling point

c)

chemical reaction

15.

Something that is made of all the same atoms or groups of atoms

a)

substance

b)

atoms

c)

scale

16.

A group of atoms joined together in a particular way

a)

product

b)

molecule

c)

fertilizer

17.

In a chemical equation the reactants are on the left side of the arrow. Are the reactants the beginning substances or the ending substances?

a)

beginning

b)

ending

18.

In a chemical equation the products are on the right side of the arrow. Are the products the beginning substances or the ending substances?

a)

beginning

b)

ending

19.

During a chemical reaction, atoms can

a)

be destroyed to form a new substance

b)

be created to form a new substance

c)

be rearranged to form a new substance

20.

Burning paper is an example of a

a)

boiling point

b)

chemical reaction

c)

extended structure

21.
the starting materials in a chemical reaction
a)
Products
b)
Reactants
c)
Starters
d)
Enders
22.
The substances listed on the right side of a chemical equation are the
a)
Yields
b)
Reactants
c)
Products
d)
Precipitates
23.

The process by which one or more substances change to produce one or more different substances

a)

Chemical Process

b)

Reactant

c)

Chemical Reaction

24.
In the equation,          2Mg + O2 ---> 2MgO, which are the reactants?
a)
Mg and O
b)
MgO
c)
Mg and MgO
d)
O and MgO
25.
What are Chemical Reactions?
a)
It's when you mix substances.
b)
a process in which atoms rearrange to form new substances
c)
When something bubbles.
d)
letter and numbers showing the types and number of atoms
26.

6CO2+ 6H2O → C6H12O6 + 6O26CO_2+\ 6H_2O\ \rightarrow\ C_6H_{12}O_{6\ }+\ 6O_2  

The carbon atoms are balanced with ____ on each side of the reaction.

a)

1

b)

6

c)

2

27.

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

a)

Balanced

b)

Unbalanced

28.

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

a)

Balanced

b)

Unbalanced

29.

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

a)

Balanced

b)

Unbalanced

30.

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

a)

Balanced

b)

Unbalanced

31.

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

32.
In this image, what are the information in red is called the_______.
a)
Product
b)
Reactant
c)
Chemical Subscript
d)
Coefficient
33.
In this image, what are the information to the right of the arrow (in black) is called the_______.
a)
Product
b)
Reactant
c)
Chemical Subscript
34.
The law of conservation of mass states that....
a)
Matter can be made
b)
Matter can be destroyed
c)
Matter can neither be made or destroyed
d)
Matter can evaporate
35.
Is the following equation balanced or unbalanced?
Fe + S --> FeS
a)
balanced
b)
unbalanced
36.
Is this balanced?...
Al + O2 --> 2Al2O3
a)
Yes!
b)
NO!
37.

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

a)

Balanced

b)

Unbalanced

38.
How many atoms of aluminum are on each side of the following equation: 4Al + 3O2 --> 2Al2 O3
a)
2
b)
6
c)
1
d)
4
39.
Grinding a seltzer tablet into powder increases the rate of reaction due to increased
a)
concentration
b)
surface area
c)
temperature
d)
reactants
40.
Which factors increase the rate of a reaction.
a)
increasing temperature
b)
increasing concentration
c)
increasing surface area
d)
all of these
41.

Match the following

Categorize the following
Chemical Reaction
Physical Change
42.

Hydrogen and oxygen react to form water. At an atomic level, how do we know that a chemical reaction has occurred?

a)

Hydrogen molecules are negative, and oxygen positive

b)

For every oxygen atom, two hydrogen atoms are needed.

c)

The hydrogen and oxygen atoms regroup into a new molecule.

d)

Oxygen atoms are much larger than hydrogen atoms.

43.

A chemical reaction occurs that involves combining 1 atom of zinc with 2 atoms hydrogen and 2 atoms of chlorine. After the reaction, how many atoms of each element will there be?

a)

1 zinc, 2 hydrogen, 2 chlorine

b)

2 zinc, 2 hydrogen, 2 chlorine

c)

2 zinc, 1 hydrogen, 2 chlorine

44.

Which of the following is the best description of the results of a chemical reaction?

a)

A new substance with different properties is formed.

b)

The substance seems to disappear after dissolving in water.

c)

The substance changes from liquid to solid at a low temperature.

d)

The reaction can be reversed to get back the original substance.

45.

During a chemical reaction, substances (called reactants) are combined to form new substances (called products). Which of the following accurately describes the reactants and the products of a chemical reaction?

a)

The products contain a different number of atoms than the reactants but have the same properties.

b)

The number of atoms and the properties are the same in the reactants and the products.

c)

The products contain the same number of atoms as the reactants but have different properties.

d)

The number of atoms and the properties are different in the reactants and the products.

46.

Four students performed four different investigations by combining different substances. Their results are shown in the table to the left. In ​ ​ (a)   , a chemical reaction took place. The other experiments ​ (b)   result in a chemical reaction.

Choose from the below words
Experiment 1
Experiment 2
Experiment 3
Experiment 4
did not
did
47.

Which observations are evidence that a chemical reaction took place?

A
B
C
D
48.

The basic unit of an element like chlorine is an ​ (a)   , whereas the basic unit of a compound like sodium chloride is a ​ (b)   .

Choose from the below words
atom
molecule
compound
crystal
49.

What is the arrow pointing to?

a)

Atom

b)

Molecule

c)

Chemical Bond

d)

Element

50.

What is circled in the picture?

a)

Atom

b)

Molecule

c)

Chemical Bond

d)

Element

51.

What is circled in the picture?

a)

Atom

b)

Molecule

c)

Chemical Bond

d)

Element

52.

The formula for hydrogen peroxide is H2O2. Which model represents hydrogen peroxide?

a)
b)
c)
d)
53.

During a reaction, atoms are

a)

created

b)

destroyed

c)

neither created or destroyed - just rearranged

54.
Which observation(s) might be used as evidence that a chemical reaction occurred?
a)
Color change
b)
Odor change
c)
Properties change
d)
All of the above
55.
_________ is (are) made of more than one atom.
a)
A molecule
b)
Protons
c)
Neutrons
d)
An element
56.
________ result(s) in no new substances.
a)
A physical change
b)
A chemical change
c)
Physical and chemical changes
d)
None of the above
57.
Which is an example of a physical change?
a)
Burning wood
b)
Freezing water
c)
Rust on a car
d)
Cooking food
58.
Which is an example of a chemical change?
a)
Burning wood
b)
Rust on a car
c)
Cooking food
d)
All of the above
59.
If you start a chemical reaction with 5 atoms of helium, how many atoms will you have after?
a)
4 atoms
b)
10 atoms
c)
1 atom
d)
5 atoms
60.
Which of the following are properties of matter?
a)
Magnetism
b)
Color
c)
Odor
d)
All of the above
61.
Which of the following help a chemical reaction to happen faster?
a)
Molecule
b)
Atom
c)
Catalyst
d)
Density
62.
Is TNT exploding a physical or chemical change?
a)
Physical
b)
Chemical
c)
Both physical and chemical
d)
Neither physical nor chemical
63.
What kind of scientist forms new materials by studying chemical reactions?
a)
Chemical engineer
b)
Materials scientist
c)
Pharmacist
d)
Medical doctor
64.

Method or means of changing one or more chemicals or chemical compounds

a)

Chemical Process

b)

Chemical Reaction

c)

Molecule

d)

Properties

65.

The smallest particle of an element; made of electrons, protons, and neutrons

a)

Atoms

b)

Elements

c)

Molecules

d)

Products

66.

The process by which one or more substances change to produce one or more different substances

a)

Chemical Process

b)

Reactant

c)

Chemical Reaction

67.

The simplest unit of a chemical compound that can exist; formed when two or more atoms join together chemically

a)

Atom

b)

Compound

c)

Molecule

68.

A solid that is deposited from a solution

a)

Solid

b)

Liquid

c)

Product

d)

Precipitate

69.

A substance produced during a chemical reaction

a)

Product

b)

Reactant

c)

Properties

70.

Physical and chemical characteristics of matter used to describe or identify a substance

a)

Chemical Reaction

b)

Properties

c)

Product

71.

A substance that takes part in and undergoes change during a reaction

a)

Product

b)

Molecule

c)

Reactant

72.

Natural resources that undergo a chemical process

a)

Properties

b)

Liquid

c)

Synthetic Materials

73.

A new substance with unique chemical and physical properties that is formed when two or more elements are chemically bonded during a chemical reaction

a)

Product

b)

Compound

c)

Molecule

d)

Atom

74.

A chemical reaction or process that absorbs heat from the surroundings

a)

Endothermic

b)

Exothermic

75.

A chemical reaction or process that releases heat.

a)

Endothermic

b)

Exothermic

76.

The tiny pieces that all matter—all the stuff in the world—is made of

a)

Electrons

b)

atoms

c)

neutrons

d)

matter

77.

Letters and numbers showing the types and number of atoms that repeat to make up a substance.

a)

Chemical reactions

b)

Molecules

c)

Chemical Properties

d)

Chemical Formula

78.

Able to cause damage

a)

Basic

b)

maleable

c)

Corrosive

d)

microscopic

79.

The temperature at which a substance changes from the solid phase to the liquid phase.

a)

Melting point

b)

Evaporation

c)

Condensation

d)

property

80.

An ending substance that is made during a chemical reaction.

a)

Reactant

b)

Product

c)

Chemical equations

d)

Formulas

81.

Something that can be observed about a substance, such as color, smell, or boiling point.

a)

Product

b)

reactant

c)

property

d)

catagory

82.

a starting substance that is part of a chemical reaction

a)

Product

b)

reactant

c)

chemical formula

d)

reactives

83.

Something that is made of all the same atoms or groups of atoms

a)

Substance

b)

product

c)

reactant

d)

chemical

84.

The diagram above shows the repeating groups of atoms that make up two samples. Will the properties of the two samples likely be the same or different? (Examples of properties are smell, color, and the temperature at which a substance melts.)

a)

The properties will likely be the same because the repeating groups of atoms that make up the two samples have two of the same types of atoms.

b)

The properties will likely be the same because the repeating groups of atoms that make up the two samples have the same number of atoms.

c)

The properties will likely be different because there are more repeating groups of atoms in Sample 2.

d)

The properties will likely be different because the repeating groups of atoms that make up each sample are different.

85.

Tiana is a chemist who is making a chemical to add to swimming pools in order to make the water safer. She mixed two solid substances together in a sealed container. The diagram above shows the repeating groups of atoms that make up the two starting substances.

After mixing, Tiana found two liquid substances in the sealed container. (Nothing had escaped.) Which of the diagrams to the left shows the repeating groups of atoms that make up the ending substances?

a)

b)

c)

d)

86.

Damian mixed two samples together: a red liquid that smells irritating and a black solid with no smell. He analyzed the results and found two ending substances. One of the ending substances was a yellow solid. This ending substance is made up of the repeating group of atoms shown above. Which of the diagrams to the left shows the repeating groups of atoms that make up the samples Damian mixed together?

a)

b)

c)

d)

87.

The diagram above shows the repeating groups of atoms that make up two samples. Both samples are liquid at room temperature. Will the properties of the two samples likely be the same or different? (Examples of properties are smell, color, and the temperature at which a substance melts.)

a)

The properties will likely be different because the repeating groups of atoms that make up the two samples have different numbers of atoms.

b)

The properties will likely be different because there are more repeating groups of atoms in Sample 1.

c)

The properties will likely be the same because both samples are liquids at room temperature.

d)

The properties will likely be the same because the repeating groups of atoms that make up the two samples have the same types of atoms.

88.

Marisol mixed two samples together: a brown liquid with no smell and a colorless gas that smells irritating. She analyzed the results and found two ending substances. One of the ending substances smelled sweet. This ending substance is made up of the repeating group of atoms shown above. Which of the diagrams to the left shows the repeating groups of atoms that make up the samples Marisol mixed together?

a)

b)

c)

d)

89.

The diagram above shows the repeating groups of atoms that make up two samples. Both samples are green gases at room temperature. Will the other properties of the two samples be the same or different? (Examples of properties are smell, color, and the temperature at which a substance melts.)

a)

The other properties will be the same because both samples are green at room temperature.

b)

The other properties will be the same because the repeating groups of atoms that make up the two samples are the same.

c)

The other properties will be different because there are more repeating groups of atoms in Sample 2..

d)

The other properties will be the same because both samples are gases at room temperature.

90.

Patrik works at a company that makes paper and needs a chemical to make the paper brighter. He mixed two colorless substances together in a sealed container. The diagram above shows the repeating groups of atoms that make up the two starting substances.

After mixing, Patrik found two white substances in the sealed container. (Nothing had escaped.) Which of the diagrams to the left shows the repeating groups of atoms that make up the ending substances?  

a)

b)

c)

d)

91.

Exceeds Question #1 (to get a 4)

A chemist mixed two substances together: a blue powder with no smell and a colorless liquid with a strong smell. Their repeating groups of atoms are shown above on the left. After they were mixed, the chemist analyzed the results and found two substances. One ending substance had the repeating group of atoms shown above on the right.

Is the ending substance the same substance as the blue powder? What happened to the atoms of the starting substances when the ending substances formed? Be sure to explain your answers to both of these questions.

4 lines
92.

Exceeds Question #2 (to get a 4)

Sahil watched a demonstration in which a scientist combined two substances in a sealed container and analyzed the results. The ending substances did not look the same as the starting substances.

Sahil was given a diagram with the repeating groups of atoms that make up the starting substances, plus information about the properties of the starting and ending substances. He created a model of the repeating groups of atoms that might make up the two ending substances.

Does his model correctly show why the properties of the ending substances are different from the properties of the starting substances? Describe what could be correct or incorrect about his model.

4 lines
93.

the tiny pieces that all matter—all the stuff in the world—is made of

a)
atoms
b)
planets
c)
cells
d)
molecules
94.

the temperature at which a substance changes from the liquid phase to the gas phase

a)
freezing point
b)
boiling point
c)
melting point
d)
condensation point
95.

letters and numbers showing the types and number of atoms that repeat to make up a substance

a)
numeric pattern
b)
alphabetical code
c)
chemical formula
d)
mathematical equation
96.

a process in which atoms rearrange to form new substances

a)
chemical reaction
b)
physical reaction
c)
biological reaction
d)
nuclear reaction
97.

able to cause damage

a)

corrosive

b)
innocuous
c)
helpful
d)
beneficial
98.

a structure formed by repeating groups of atoms linked together in a large network

a)

extended structure

b)
element
c)
monomer
d)
isotope
99.

a substance that is added to soil to help plants grow

a)
fungicide
b)
fertilizer
c)
herbicide
d)
pesticide
100.

the temperature at which a substance changes from the solid phase to the liquid phase

a)
Melting point
b)
Condensation point
c)
Freezing point
d)
Boiling point
101.

an object, diagram, or computer program that helps us understand something by making it simpler or easier to see

a)
model
b)
confusion
c)
complication
d)
painting
102.

a group of atoms joined together in a particular way

a)
molecule
b)
cell
c)
organism
d)
rock
103.

an ending substance that is made during a chemical reaction

a)
product
b)
reactant
c)
catalyst
d)
ingredient
104.

something that can be observed about a substance, such as color, smell, or boiling point

a)
physical property
b)
metaphysical property
c)
spiritual property
d)
emotional property
105.

a starting substance that is part of a chemical reaction

a)
catalyst
b)
product
c)
reactant
d)
inhibitor
106.

to change the order or position of something

a)
rearrange
b)
shuffle
c)
maintain
d)
disorder
107.

the relative size of things

a)
magnitude
b)
proportion
c)
dimension
d)
scale
108.

something that is made of all the same atoms or groups of atoms

a)
compound
b)
mixture
c)
solution
d)

substance

109.

How often do chemists from a city's water department test the water supply?

a)

every hour

b)

every day

c)

every week

d)

every month

e)

every year

110.

Where did Dr. Yung (the chemist near Westfield) find the reddish-brown substance when she examined all the possible sources?

a)

coming from the pipes into the houses

b)

in the wells where the water comes from

c)

in the ponds nearby the town

d)

in all water everywhere in Westfield

111.

When examining the following evidence, which is the best evidence we should use?

a)

ugly color, solid

b)

white, small pieces

c)

white, small, grainy, crystals

112.

Consider the following substance descriptions. Does the evidence support that they are the same substances?

Substance 1: white, small, grainy, crystals

Substance 2: black, fine powder.

a)

YES

b)

NO

113.

Consider your answer to the previous question:

Consider the following substance descriptions. Does the evidence support that they are the same substances?

Substance 1: white, small, grainy, crystals

Substance 2: black, fine powder.

What is the best explanation for why this substance is the same or different?

a)

The visual properties of the two substances are different.

b)

They don't look the same so they are not the same.

c)

They are the same because they are both small tiny pieces.

d)

There is no way to determine if they are the same/different based on this information.

114.

Are these two samples the same substance?

a)

They are the same substances because they are both white powders.

b)

They are the same substances because they both have similar atomic structures.

c)

They are different substances because they have different atoms making them up.

d)

They are the same because they both have the same number of atoms.

115.

Select the FALSE definition for "Repeating groups of atoms"

a)

Repeating atoms are atoms that replicate themself.

b)

Repeating groups of atoms are substances made of the same group of atoms repeated over and over.

c)

Molecules are groups of atoms that form specific groups that are each separate and can range in size from two atoms to thousands of atoms.

d)

Extended structures are substances that in solid phase are made of many atoms or many groups of atoms that connect to form a large structures called crystals.

116.

Why do different substances have different properties?

a)

They are made of different groups of atoms.

b)

They look different.

c)

The same atoms can change their properties when needed.

d)

There are different numbers of the repeating atom groups.

117.

What is the reddish-brown substance in the water of Westfield?

Select the BEST answer.

a)

The reddish-brown substance is the same as the substance that makes up the pipes.

b)

The reddish-brown substance is the same substance as the fertilizer.

c)

The reddish-brown substance is different from both the fertilizer and the pipes.

d)

The reddish-brown substance is iron oxide or rust.

118.

The tiny pieces that all matter--all the stuff in the world--is made of ...

a)

atoms

b)

protons

c)

molecules

d)

electrons

119.

The temperature at which a substance changes from the liquid phase to the gas phase...

a)

freezing point

b)

melting point

c)

boiling point

d)

high temperature

120.

A structure formed by repeating groups of atoms that link together in a large network...

a)

extended structure

b)

atoms

c)

molecules

d)

proteins

121.

The temperature at which a substance changes from the solid phase to the liquid phase....

a)

boiling point

b)

meling point

c)

liquid point

d)

condensation point

122.

An object, diagram, or computer program that helps us understand something by making it simpler or easier to see...

a)

model

b)

atom

c)

simulator

d)

experiment

123.

A group of atoms joined together in a particular way...

a)

molecule

b)

atom

c)

extended structure

d)

property

124.

Something that can be observed about a substance, such as color, smell, or boiling point...

a)

property

b)

chemistry

c)

substance

d)

molecule

125.

The relative size of things...

a)

Scale

b)

Measurement

c)

Molecule

d)

Big and Small

126.

Something that is made of all the same atoms or groups of atoms...

a)

substance

b)

atoms

c)

chemical formula

d)

molecule

127.

Scientists can use properties to help them distinguish between different substances.

a)

True

b)

False

128.

All properties used to distinguish substances can be found with visual observations.

a)

True

b)

False

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