Name: Date:
Chemical Changes
Directions: Follow the instructions to go through the simulation. Respond to the questions and
prompts in the orange boxes.
Vocabulary: acid, base, catalyst, chemical change, coefficient, conservation of matter, decomposition,
dissolve, double replacement, endothermic, exothermic, indicator, ion, physical change, product, reactant,
single replacement, subscript, synthesis
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
1. A student mixes baking soda and vinegar in a glass. The results are shown at
left. Do you think any new substances are being created in this mixture? If so,
how do you know?
Yes, there are new substances being created in this mixture because there
is bubbling, a sign of a chemical change.
2. Suppose this was done on top of a balance. Do you think the mass would
change as the reaction proceeded?
The mass would stay the same.
3. What do you think would happen to the mass if the reaction took place inside a sealed plastic bag?
The mass would most likely be slightly heavier since the gas is contained.
Gizmo Warm-up
A chemical change, (or chemical reaction) occurs when one or more
substances, called reactants, are transformed into different substances, or
products. In the Chemical Changes Gizmo, you will look for evidence of
chemical changes by looking at changes you can see, touch, or smell.
To begin, check that Reactant 1 is Sodium and Reactant 2 is Water.
Sodium is a metal so soft you can cut it with a knife.
1. Click Play ( ). What do you observe?
When the sodium was placed inside the water, it started bubbling, gaining weight, and changing color.
Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved
, 2. Do you think a chemical reaction has taken place? Explain.
A chemical reaction has taken place because there are chemical changes present like a change in color.
Activity A: Get the Gizmo ready:
● Click Reset ( ). Check that the reactants are
Observing still Sodium and Water.
chemical changes ● Turn on the Label reactants checkbox.
Introduction: It is important to distinguish chemical changes, in which new substances are formed, from
physical changes, which do not create new substances. In this activity, you will look at many kinds of
evidence that chemists use to see if a chemical change has taken place.
Question: What kinds of evidence indicate a chemical change has taken place?
1. Observe: Some chemical reactions release heat, and others absorb heat. In an exothermic reaction, heat is
released and the temperature of the system rises. In an endothermic reaction, heat is absorbed and the
temperature of the system decreases.
In the Gizmo, drag the Thermometer into the flask of water.
A. What is the starting temperature? 21°C
B. Click Play, and wait for the reaction to end. What is the final temperature? 59°C
C. Was this reaction exothermic or endothermic? Exothermic
2. Observe: Two families of chemicals are acids and bases. Acids and bases can be detected by an
indicator, which is a substance that changes color in the presence of an acid or a base. Phenol red is an
indicator that is yellow in an acid, orange in a neutral solution, and pink in a base.
A. Click Reset. Drag the Phenol red next to the flask of water. What does the indicator show?
A neutral pH and is the color orange.
B. Click Play, and wait for the reaction to end. What does the indicator show now?
A basic pH and is the color pink.
3. Observe: Click Reset. Select the Gas collection setup. Chemists use this apparatus to collect any gases
produced in the reaction. From the reaction flask, gases travel through a long tube and into a cylinder of
water. As gases bubble into the cylinder, the water is displaced (removed) until the cylinder is filled with
gas.
Click Play and observe the cylinder. Was any gas produced in the reaction?
Yes, there was gas produced in the reaction.
Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved
Chemical Changes
Directions: Follow the instructions to go through the simulation. Respond to the questions and
prompts in the orange boxes.
Vocabulary: acid, base, catalyst, chemical change, coefficient, conservation of matter, decomposition,
dissolve, double replacement, endothermic, exothermic, indicator, ion, physical change, product, reactant,
single replacement, subscript, synthesis
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
1. A student mixes baking soda and vinegar in a glass. The results are shown at
left. Do you think any new substances are being created in this mixture? If so,
how do you know?
Yes, there are new substances being created in this mixture because there
is bubbling, a sign of a chemical change.
2. Suppose this was done on top of a balance. Do you think the mass would
change as the reaction proceeded?
The mass would stay the same.
3. What do you think would happen to the mass if the reaction took place inside a sealed plastic bag?
The mass would most likely be slightly heavier since the gas is contained.
Gizmo Warm-up
A chemical change, (or chemical reaction) occurs when one or more
substances, called reactants, are transformed into different substances, or
products. In the Chemical Changes Gizmo, you will look for evidence of
chemical changes by looking at changes you can see, touch, or smell.
To begin, check that Reactant 1 is Sodium and Reactant 2 is Water.
Sodium is a metal so soft you can cut it with a knife.
1. Click Play ( ). What do you observe?
When the sodium was placed inside the water, it started bubbling, gaining weight, and changing color.
Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved
, 2. Do you think a chemical reaction has taken place? Explain.
A chemical reaction has taken place because there are chemical changes present like a change in color.
Activity A: Get the Gizmo ready:
● Click Reset ( ). Check that the reactants are
Observing still Sodium and Water.
chemical changes ● Turn on the Label reactants checkbox.
Introduction: It is important to distinguish chemical changes, in which new substances are formed, from
physical changes, which do not create new substances. In this activity, you will look at many kinds of
evidence that chemists use to see if a chemical change has taken place.
Question: What kinds of evidence indicate a chemical change has taken place?
1. Observe: Some chemical reactions release heat, and others absorb heat. In an exothermic reaction, heat is
released and the temperature of the system rises. In an endothermic reaction, heat is absorbed and the
temperature of the system decreases.
In the Gizmo, drag the Thermometer into the flask of water.
A. What is the starting temperature? 21°C
B. Click Play, and wait for the reaction to end. What is the final temperature? 59°C
C. Was this reaction exothermic or endothermic? Exothermic
2. Observe: Two families of chemicals are acids and bases. Acids and bases can be detected by an
indicator, which is a substance that changes color in the presence of an acid or a base. Phenol red is an
indicator that is yellow in an acid, orange in a neutral solution, and pink in a base.
A. Click Reset. Drag the Phenol red next to the flask of water. What does the indicator show?
A neutral pH and is the color orange.
B. Click Play, and wait for the reaction to end. What does the indicator show now?
A basic pH and is the color pink.
3. Observe: Click Reset. Select the Gas collection setup. Chemists use this apparatus to collect any gases
produced in the reaction. From the reaction flask, gases travel through a long tube and into a cylinder of
water. As gases bubble into the cylinder, the water is displaced (removed) until the cylinder is filled with
gas.
Click Play and observe the cylinder. Was any gas produced in the reaction?
Yes, there was gas produced in the reaction.
Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved
