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Unit 3 Chemical Reactions Review (2021)

Total questions: 46

Worksheet time: 33mins

Name
Class
Date
1.
Which liquid is the least dense?
a)
oil
b)
water
c)
syrup 
d)
plastic bottle
2.
Why does ice float?
a)
Liquid water is less dense than solid water.
b)
Solid water is less dense than liquid water.
c)
Gaseous water is less dense than solid water.
d)
Liquid water is less dense than gaseous water.
3.

What kind of properties can only be observed when a substance changes into a new and different substance?

a)

physical properties

b)

chemical properties

c)

liquid properties

d)

real properties

4.
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
5.
Is hammering wood together to build a house a chemical or physical change?
a)
chemical
b)
physical
6.
Is melting butter for popcorn a chemical or physical change?
a)
chemical
b)
physical
7.
Is bleaching your hair a physical or chemical change?
a)
physical
b)
chemical
8.
Is burning wood a chemical or physical change?
a)
chemical
b)
physical
9.
A change in the size, shape, or state of matter.
a)
chemical change
b)
physical change
c)
chemical reaction
d)
electron change
10.
Kim puts an ice cube in a beaker and it melts. This is a good example of:
a)
a physical change.
b)
a chemical change.
c)
an experiment.
d)
an analysis.
11.
Photosynthesis is an example of a
a)
physical change
b)
chemical change
12.
Adding baking soda and vinegar together and it fizzes and creates carbon dioxide.
a)
Chemical
b)
Physical
13.
what is the definition of chemical change?
a)
any change that results in the formation of new chemical substances. 
b)
changing clothes
c)
matter cannot be created or destroyed, only change form
d)
changes affecting the form of a chemical substance, but not its chemical composition.
14.
All matter is made of
a)
atoms
b)
cells
15.
The atomic number tells you what?
a)
number of electrons
b)
number of protons
c)
number of neutrons
d)
both electrons and protons in an atom.
16.
What does the 1.00794 stand for?
a)
Hydrogen
b)
atomic number
c)
atomic mass
d)
atomic explosion
17.
How many protons are in Beryllium?
a)
4
b)
9
c)
5
d)
2
18.
What is the chemical symbol for Lithium?
a)
H
b)
He
c)
Li
d)
N
19.
Most of the elements on the periodic table are classified as "metal".
a)
True
b)
False
20.

How many elements are liquid at room temperature?

a)

Most of them.

b)

Two of them.

c)

11 of them.

d)

None of them.

21.

Which is true about the element Tungsten (W)?

a)

It is a noble gas.

b)

It is a solid non-metal.

c)

It is a solid alkali metal.

d)

It is a solid metal.

22.

Which is NOT true about the families of the Periodic Table?

a)

Family #18 is the Noble Gases. They are very safe and stable.

b)

Family #1 is the Alkali Metals. They are very unstable and will explode if placed in water.

c)

All elements in the same family (or group) have very similar properties, just like the members of your own family.

d)

Families are organized by the state of matter of each element. In other words, all liquids are in the same family, all solids are in the same family, and all gases are in the same family.

23.

The last column on the Periodic Table of Elements, Family 18, are very stable and don't react with any thing. They are called the....

a)

Alkali Metals

b)

Unreactive Elements

c)

Noble Gases

d)

Non-Metals

24.

Family #1 is called the Alkali Metals and they...

a)

are very safe and stable

b)

are all liquids and gases

c)

smell like chicken

d)

are all very volatile and explode if placed in water

25.

How many total atoms does this molecule contain?

a)

a billion

b)

5

c)

2

d)

11

26.

How many different elements is this molecule made up of?

a)

2

b)

3

c)

11

d)

746354242637495050398376125651142563637373

27.

How many total elements are in one molecule of table salt?

a)

1

b)

2

c)

3

d)

4

28.

How many total atoms are in one molecule of table salt?

a)

1

b)

2

c)

3

d)

4

29.
When a scientist mixed two chemicals, an exothermic reaction takes place. Which of the following would be proof that the reaction was exothermic?
a)
a change of color
b)
a change of state
c)
a temperature decrease
d)
a temperature increase
30.

Which of the following is a chemical change?

a)

water freezes to form ice

b)

sugar dissolves in water

c)

gasoline burns in a car engine

d)

a piece of metal expands when it is heated

31.
In the reaction methane + oxygen turns into carbon dioxide + water, the methane and oxygen are called _______________.
a)
reactants
b)
products
c)
neutrals
d)
energizers
32.

If you combine two substances in a flask at room temperature and the beaker feels cold to the touch, it means that the substances:

a)

have not reacted with each other

b)

have undergone an endothermic reaction

c)

have undergone a physical change

d)

have undergone an exothermic reaction

33.

In any chemical reaction, the mass of the products is always:

a)

slightly less than the mass of the reactants

b)

much less than the mass of the reactants

c)

the same as the mass of the reactants

d)

greater than the mass of the reactants

34.

The Law of Conservation of Mass states that during a normal chemical reaction, mass is NOT ________________________, the atoms are just rearranged to form new substances.

a)

created or destroyed

b)

bent and twisted

c)

lost and found

d)

weighed and measured

35.
If reaction starts with 20g of reactants it should produce 
a)
a total of 40g of products
b)
a total of 10g of products
c)
a total of 80 g of products
d)
a total of 20g of products
36.
What type of reaction occurs in a hand warmer
a)
exothermic
b)
endothermic
37.
Is photosynthesis an exothermic or endothermic reaction?
a)
Endothermic
b)
Exothermic
c)
Neither
38.

Natural Resources are created...

a)

in a factory.

b)

in a laboratory.

c)

by mother nature or the Earth.

d)

from thin air.

39.

Which one of these is a RENEWABLE resource?

a)

oil

b)

crops

c)

natural gas

d)

gold

40.

A synthetic product is created...

a)

by mother nature or the Earth.

b)

in a factory of a lab by humans.

c)

deep underground in a mine.

41.

Which one of these is NOT a positive impact of synthetic products?

a)

Many are made using non-renewable resources.

b)

They are cheaper to make than natural products.

c)

They are easier and faster to make than natural products.

d)

Many are stronger and more durable.

42.

Synthetic products are made by humans in a factory or lab using a.....

a)

chemical reaction

b)

large machine

c)

toxic chemicals

d)

millions and billions of molecules

43.

What are the two kinds of natural resources?

a)

renewable and infinite

b)

renewable and noninfinite

c)

nonrenewable and finite

d)

nonrenewable and renewable

44.

You can make synthetic products from these things...

a)

Plant based resources

b)

Animal based resources

c)

Petroleum based resources

d)

All of the above

45.
What are the 3 main fossil fuels?
a)
A. Coal, oil, and vegetable oil. 
b)
B. Coal, Oil, and Natural Gas
c)
C. Electricity, Gasoline, Petroleum
d)
D. Coal, Oil, Non-renewable Resources
46.

Synthetic materials are not biodegradable, made from non-renewable resources, are often highly flammable, and require large amounts of energy to produce. These impacts are all considered to be __________________ associated with using synthetic materials.

a)

positive benefits

b)

negative drawbacks