States of Matter
Pure Substance or Mixture
Physical or Chemical Change
Signs of a Reaction
100
This state of matter has no definite volume and no definite shape
What is a gas?
100
A combination of different types of matter that are not chemically bonded.
What is a mixture?
100
A ________ change is when a new substance is formed.
chemical
100
Name one of the 5 signs that indicate a chemical reaction may have happened.
Gas production
Light emission
Temperature change
Color change
Precipitate forms (solid from liquid)
200
Describe the motion of particles in a liquid.
Particles are close and slide/flow past one another
200
A gold bar is made of just gold atoms. Is this a pure substance or mixture?
Pure substance
200
When a substance changes form or appearance, but the identity stays the same.
What is a physical change?
200
The statue of liberty is made out of copper and used to be brownish/gold. Over time, it has tarnished, which gave it it's green color. What sign of a chemical reaction do we observe here?
Color change
300
The temperature that water freezes (in celsius).
What is 0C
300
Air is actually a combination of several gases, such as oxygen (O2) gas, nitrogen, and carbon dioxide. Air is considered a _______.
mixture
300
Paper is cut into tiny pieces. Explain why this is a physical change.
The paper is still the same substance even after it is cut.
300
When you mix coke and mentos, it create a fizzy geyser that shoots out of the bottle, an exciting example of a chemical change! What sign of a chemical reaction is observed here?
Gas production
400
Adding heat to a substance will make its particles... _______.
Move faster/gain more energy/spread apart
400
Salt water is a mixture made when salt is dissolved in water and is evenly distributed. This kind of mixture is called a _______.
A solution
400
Explain why burning a piece of paper is considered a chemical change.
Burning paper creates new substances (smoke, ash)
400
A student mixes two substances together in a beaker with a thermometer. The student notices the thermometer drops from 22oC to 14oC. What sign of a chemical change did the student observe?
Temperature change
500
When a solid changes directly to a gas.
What is sublimation?
500
Water is really good at dissolving many substances. Dissolvers are called ______.
solvents
500
"A student claims that water freezing is a chemical change because it creates a substance with a new identity." Explain whether this student is right or wrong.
Student is incorrect - when water freezes, it is still the same substance, just in solid form
500
A student mixes two clear liquids in a beaker. After a few seconds, they notice a solid begins to form and settles on the bottom, a classic sign of a chemical change! What is the name for a solid that forms from liquids reacting?
Precipitate