Reversible and Irreversible Changes
Burning is an example of what kind of change?
Irreversible
When you eat food and your body uses it for energy, this is an example of a ___________.
Chemical change
Explain how melted chocolate can be reversed back to its original form.
Melting chocolate can be reversed by cooling the chocolate again until it hardens.
The prediction; educated guess
The hypothesis
The process by which a gas changes state to become a liquid
Condensation
Melting chocolate is an example of what kind of change?
Reversible
Physical change
Explain how dissolving salt in water can be reversed back to its original form.
Dissolving salt in water can be reversed back to salt and water again by the process of evaporation.
A model or guide used to gather information about the world and solve problems
The scientific method
The process by which a liquid becomes a gas
Evaporation
True or False. Changes to some mixed materials can be reversed by evaporation.
True
When baking soda and vinegar are combined, they produce ___________.
Carbon dioxide
Explain how boiling water can be reversed back to its original form.
Boiling water can be reversed until it condenses from a gas to a liquid.
The steps of an experiment; a certain pattern or way of doing something
The procedure
The process by which a liquid becomes a solid
Freezing
True of false. If you beat an egg, its chemical composition will change.
False
When one or more of the original substances changes into other substances, it is called a ___________.
Chemical change
Explain how condensation on a water bottle can be reversed back to its original form.
Condensation on a water bottle can be reversed back into the air through evaporation.
What is the first step of the scientific method?
Asking a question about something you observe
Substances that start a chemical reaction are called __________
Reactants
Name two ways you could make a solid dissolve faster in water.
Heat up the water, stir it
Most matter can undergo ___________, which is any change in size, shape, or form
Physical change
Explain how toasting bread can be reversed back to its original form.
You can't! Trick question!!! Toasting bread is a chemical and irreversible change as the bread becomes a new substance when toasted.
In the following statement, what is the hypothesis? August and Melody noticed that many of the plants in the school yard were dying. They saw some June bugs in the area one day. They wanted to figure out what was happening to the plants. They think that if June bugs live near the plants, then they will die faster than plants without the June bugs.
"if June bugs live near the plants, then they will die faster than plants without the June bugs."
Substances that are produced in a chemical reaction are called ___________
Products.