Physical Changes
What happens to the size of a basketball when air is added?
The basketball expands because it fills up the space with air.
What is a sign that a chemical change has occurred?
A change in color, temperature, or the production of gas or precipitate.
What do we call a mixture where one substance dissolves in another?
A solution.
What is one property you can use to identify baking soda?
It is a white powder and has a slightly gritty texture.
What is it called when a solid turns into a liquid?
Melting.
What is an example of a physical change when ice melts?
Ice turns into water; it changes state from solid to liquid.
What happens when vinegar is mixed with baking soda?
A chemical reaction occurs, producing gas bubbles (carbon dioxide).
When you stir sugar into water and it disappears, what happened to the sugar?
The sugar dissolved in the water.
How can you tell if a metal is conductive?
You can test if it allows electricity to pass through.
What happens to water when it freezes?
It changes from liquid to solid.
If you mix sand and salt, what type of change is that?
It is a physical change because the substances can be separated again.
How can you tell a chemical change from a physical change?
In a chemical change, the substances change into new substances.
What is an example of a mixture that can be separated by physical means?
A salad can be separated back into its individual ingredients.
What does it mean if a liquid is clear and shiny?
It may have high reflectivity and could be a property of water or oil.
What is the process called when a liquid changes to a gas?
Evaporation.
Can you name a physical change that occurs when you heat water?
Water boils and turns into steam, which is a change in state.
What is an example of a chemical change when cooking?
Baking a cake, where the ingredients change into a new product.
What happens to the weight of substances when they dissolve in water?
The total weight of the mixture remains the same.
What property describes how easily a material can be scratched?
Hardness.
When water vapor cools and turns back into liquid, what is this process?
Condensation.
What is the main characteristic of a physical change?
The substance remains the same even though it changes form.
What is the law of conservation of mass in chemical reactions?
Matter cannot be created or destroyed in a chemical reaction; it is conserved.
What is the difference between a solution and a mixture?
A solution has a uniform composition, while a mixture can have a varied composition.
Why is color an important property in identifying materials?
Different materials have different colors, which can help us tell them apart.
What do we call the change of state from gas directly to solid?
Deposition.