Chemical Reactions: Interactive Quizzes for 4th Grade Science

Question 1

When hydrogen and oxygen are combined to form water, which of these equations correctly represents the chemical reaction?

Accepted Answer

2H + O2 → H2O

Answer

H + O → H2O

Answer

H2 + O → H2O2

Answer

H2O → H + O2

Question 2

Which of these is a chemical reaction where a substance combines with oxygen and releases energy as heat and light?

Accepted Answer

Burning of wood

Answer

Rusting of iron

Answer

Dissolving salt in water

Answer

Mixing vinegar and baking soda

Question 3

When a chemical reaction occurs, what observable changes might you notice?

Accepted Answer

A new color appears.

Accepted Answer

The mixture changes temperature.

Accepted Answer

Bubbles form in the mixture.

Answer

The mixture changes weight.

Question 4

Which of these is NOT a sign that a chemical reaction has occurred?

Accepted Answer

No change in appearance

Answer

A color change

Answer

The formation of a gas

Answer

A change in temperature

Question 5

What is an example of a chemical change?

Accepted Answer

Wood burning

Answer

Ice melting

Answer

Paper tearing

Answer

Salt and water mixing

Question 6

Which of the following is NOT a chemical reaction?

Accepted Answer

Forming a solid from a solution

Answer

Combining two or more substances to form a single product

Answer

Breaking down a single substance into two or more products

Answer

A substance reacting with oxygen, releasing heat and light

Question 7

What happens when new substances are created or old substances are separated?

Accepted Answer

Chemical reaction

Answer

Physical change

Answer

Melting

Answer

Evaporation

Question 8

What does NOT indicate a chemical reaction?

Accepted Answer

Salt dissolving in water

Answer

Color change

Answer

Bubbles forming

Answer

Temperature change

Question 9

During a science experiment, you mix two different liquids together. You notice that the mixture changes color and starts to bubble. Which of the following is most likely happening?

Accepted Answer

A chemical reaction is occurring.

Answer

The liquids are simply mixing together.

Answer

The liquids are evaporating.

Answer

The liquids are reacting with the air.

Question 10

Which of these is NOT a sign that a chemical reaction is taking place?

Accepted Answer

Change in state

Answer

Change in temperature

Answer

Change in color

Answer

Formation of a gas

Question 11

When we combine vinegar and baking soda, we see bubbles forming. What is occurring during this chemical reaction?

Accepted Answer

A new substance called carbon dioxide is created.

Answer

Vinegar transforms into baking soda.

Answer

Baking soda transforms into vinegar.

Answer

Vinegar and baking soda do not react.

Question 12

In a science experiment, you combine two clear liquids and notice that the mixture turns a vibrant green color. Which of the following is the most probable explanation for this observation?

Accepted Answer

A chemical reaction has taken place.

Answer

The temperature of the mixture has altered.

Answer

A gas has formed within the mixture.

Answer

The mixture's shape has changed.

Question 13

When a chemical change happens, we can often see signs that tell us it has occurred. Which of these is NOT a sign that a chemical change has taken place?

Accepted Answer

The color remains the same.

Answer

The smell changes.

Answer

The temperature changes.

Answer

Bubbles form.

Question 14

When sodium reacts with oxygen, what type of chemical reaction occurs?

Accepted Answer

Combination Reaction

Answer

Decomposition Reaction

Answer

Single Displacement Reaction

Answer

Double Displacement Reaction

Question 15

When you mix baking soda and vinegar, the mixture bubbles and gets warm. What is the best explanation for this?

Accepted Answer

The baking soda and vinegar are creating a new substance.

Answer

The baking soda and vinegar are changing shape.

Answer

The baking soda and vinegar are getting hotter because of the sun.

Answer

The baking soda and vinegar are bubbling because they are being stirred.

Question 16

What are some signs that a chemical reaction is taking place?

Accepted Answer

A new color appears

Accepted Answer

The temperature changes

Accepted Answer

A solid forms in a liquid

Answer

Water evaporates

Question 17

Which of these is NOT a sign that a chemical reaction has happened?

Accepted Answer

No change in appearance

Answer

A change in color

Answer

A change in temperature

Answer

The formation of a new substance

Question 18

Which of the following is NOT a sign that a chemical reaction has occurred?

Accepted Answer

No gas production

Answer

Temperature change

Answer

Change in color

Answer

Different smell

Question 19

When a substance transforms its chemical structure, it undergoes a chemical change. Which of these actions demonstrates a chemical change?

Accepted Answer

Burning paper

Answer

Melting ice

Answer

Dissolving sugar in water

Answer

Chopping wood

Question 20

When a chemical reaction occurs, which of the following is a sign that it is taking place?

Accepted Answer

A change in color

Accepted Answer

A change in temperature

Accepted Answer

The formation of bubbles

Answer

A loud sound

Question 21

When two chemicals are mixed, which of these is NOT a sign that a chemical reaction has occurred?

Accepted Answer

Ingredients simply mixing together

Answer

Fizzing

Answer

Color change

Answer

Heat release

Question 22

What is the result of a chemical reaction?

Accepted Answer

A new substance is formed

Answer

The temperature of the substances rises

Answer

The substances change their shape

Question 23

When you mix baking soda and vinegar, you see bubbles forming. What does this tell you about the baking soda and vinegar?

Accepted Answer

They are changing into a new substance.

Answer

They are getting hotter.

Answer

They are getting lighter.

Question 24

What happens to the energy involved in a chemical reaction?

Accepted Answer

Energy can be released or absorbed, depending on the reaction.

Answer

Energy is always released.

Answer

Energy is always absorbed.

Question 25

On the periodic table, where are metals typically found in relation to non-metals?

Accepted Answer

Metals are on the left, and non-metals are on the right.

Answer

Metals are on the top, and non-metals are on the bottom.

Answer

Metals and non-metals are mixed together.

Answer

There is no pattern.

Question 26

When you stir sugar into water and it dissolves, is a chemical reaction occurring?

Accepted Answer

No, because the sugar is still present in the water.

Answer

Yes, because the sugar changes form.

Question 27

What is an example of a chemical reaction?

Accepted Answer

Burning paper

Answer

Water freezing

Answer

Dissolving sugar in water

Question 28

When you see a change in color, temperature, bubbling, or a change of state in a mixture, what is most likely happening?

Accepted Answer

A chemical reaction

Answer

A physical change

Answer

A mixture of substances

Answer

A change in the environment

Question 29

Which of these is NOT a type of chemical reaction that we learned about in this unit?

Accepted Answer

Nuclear Fusion

Answer

Combination

Answer

Decomposition

Answer

Single Displacement

Question 30

On a hot summer day, a puddle of water gradually vanishes. What's happening to the water?

Accepted Answer

Evaporating into water vapor

Answer

Freezing into ice

Answer

Condensing into clouds

Answer

Boiling into steam

Question 31

What type of chemical reaction occurs when two or more substances combine to form a single new substance?

Accepted Answer

Combination

Answer

Decomposition

Answer

Single displacement

Answer

Double displacement

Question 32

During a chemical reaction, what happens to the atoms involved?

Accepted Answer

They are rearranged into different molecules.

Answer

They are created or destroyed.

Answer

They gain or lose electrons.

Question 33

Which of these is NOT a sign that a chemical reaction has occurred?

Accepted Answer

The shape changes

Answer

A color change

Answer

A gas is produced

Answer

The temperature changes

Question 34

What type of chemical reaction happens when baking soda and vinegar are mixed together?

Accepted Answer

Neutralization reaction

Answer

Combination reaction

Answer

Decomposition reaction

Question 35

Which of these is NOT a sign that a chemical reaction has taken place?

Accepted Answer

No change in appearance

Answer

A change in color

Answer

The release of gas

Answer

A change in temperature

Question 36

What are some signs that a chemical reaction has happened?

Accepted Answer

A change in color

Accepted Answer

A change in temperature

Accepted Answer

A change in smell

Answer

A change in shape

Question 37

In a **neutralization** reaction, which substances react to form a new substance?

Accepted Answer

Acid and base

Answer

Salt and water

Answer

Metal and nonmetal

Question 38

When a reaction takes place and heat is absorbed from the surroundings, what type of reaction is it?

Accepted Answer

Endothermic reaction

Answer

Exothermic reaction

Question 39

Which of the following is NOT a type of chemical reaction we have studied in this unit?

Accepted Answer

Photosynthesis

Answer

Combustion

Answer

Oxidation

Answer

Neutralization

Question 40

What do we call the reaction that takes place when a base combines with an acid?

Accepted Answer

Neutralization

Answer

Combustion

Answer

Oxidation

Answer

Decomposition

Question 41

Which of the following is NOT a sign that a chemical reaction is happening?

Accepted Answer

No noticeable change

Answer

Change in color

Answer

Release of heat or light

Answer

Formation of bubbles (gas)

Question 42

What is the main role of a catalyst in a chemical reaction?

Accepted Answer

Speeds up the reaction

Answer

Slows down the reaction

Answer

Stops the reaction

Answer

Reverses the reaction

Question 43

Which of the following is an example of a chemical change?

Accepted Answer

Burning a leaf

Answer

Ice melting

Answer

Water boiling

Answer

Sugar dissolving in water

Question 44

What is the main difference between a reactant and a product in a chemical reaction?

Accepted Answer

Reactants are the initial substances, products are the final substances

Answer

Products are the initial substances, reactants are the final substances

Answer

Reactants are gases, products are solids

Answer

Products are gases, reactants are solids

Question 45

Which of the following is NOT a safety precaution to follow when working with chemicals in a lab?

Accepted Answer

Use a fan to speed up chemical reactions

Answer

Tie long hair back

Answer

Wear a lab coat and safety goggles

Answer

Keep food and drinks away from the lab area

Question 46

Which of the following is NOT a characteristic of a chemical reaction?

Accepted Answer

Change in color only

Answer

Formation of a new substance

Answer

Change in energy

Question 47

During a chemical reaction, what typically changes?

Accepted Answer

The materials involved

Answer

The temperature

Answer

The appearance

Answer

The shape

Question 48

What happens when you combine vinegar and baking soda?

Accepted Answer

It fizzes

Answer

It burns

Answer

It rusts

Question 49

When sodium and chlorine atoms interact, they form a new substance called sodium chloride. What type of chemical reaction is this?

Accepted Answer

Combination Reaction

Answer

Decomposition Reaction

Answer

Single-Displacement Reaction

Answer

Double-Displacement Reaction

Question 50

What is an example of a chemical change, where the chemical composition of a substance changes?

Accepted Answer

Wood burning

Answer

Ice melting

Answer

Sugar dissolving in water

Answer

Can being crushed

Question 51

How do catalysts affect chemical reactions?

Accepted Answer

Catalysts speed up reactions.

Answer

Catalysts change the products of reactions.

Answer

Catalysts create new types of reactions.

Question 52

Which of these does NOT affect how fast a chemical reaction happens?

Accepted Answer

Size of the container

Answer

Temperature

Answer

Amount of reactants

Answer

Type of reactants

Question 53

Which of these changes involves a new substance being formed?

Accepted Answer

Wood burning

Answer

Ice melting

Answer

Salt dissolving in water

Answer

Water freezing

Question 54

What happens during a chemical reaction when chemicals transform?

Accepted Answer

New substances with different properties are formed

Answer

The chemicals vanish, leaving nothing behind

Answer

The chemicals remain unchanged

Answer

Only dangerous and poisonous substances are produced

Question 55

Which of these is an example of burning?

Accepted Answer

Lighting a candle

Answer

Rusting of iron

Answer

Dissolving of salt in water

Question 56

When ice melts, is that a chemical change or a physical change?

Accepted Answer

Physical change

Answer

Chemical change

Question 57

True or False: In most chemical reactions, energy is released and things get warmer.

Accepted Answer

True

Answer

False

Question 58

What is the special power of a material called a catalyst?

Accepted Answer

It speeds up reactions without being used up

Answer

It slows down reactions without being used up

Answer

It changes the final products of the reaction

Question 59

Lemons are sour because they contain:

Accepted Answer

Acid

Answer

Base

Answer

Salt

Question 60

What is the chemical code for the substance we call water?

Accepted Answer

H2O

Answer

CO2

Answer

NaCl

Question 61

Which of these is a source of energy that we can use again and again?

Accepted Answer

Sunlight

Answer

Coal

Answer

Natural gas

Question 62

When a substance combines with oxygen, what process does it undergo?

Accepted Answer

Oxidation

Answer

Combustion

Answer

Neutralization

Answer

Reduction

Question 63

What are the products of a combustion reaction?

Accepted Answer

Water and carbon dioxide

Answer

Salt and water

Answer

Acid and base

Answer

Hydrogen and oxygen

Question 64

Which of the following is an example of an acid-base reaction?

Accepted Answer

Mixing vinegar and baking soda

Answer

Burning wood

Answer

Rusting iron

Answer

Dissolving sugar in water