Vocabulary
The amount of space an object takes up.
What is volume?
Which of these would describe a chemical reaction?
(colorless, odorless, liquid at 20 degrees, reacts with oxygen)
What is reacts with oxygen?
What kind of change is a change of state? Why?
What is a physical change? It is a physical change because the chemical make-up of the substance is not changing.
Solid to Liquid
What is melting?
Making lemonade. Explain why.
What is physical? The sugar and water could be separated.
This can be observed or measured without changing the composition of the substance.
What is a physical property?
Give 3 examples of chemical changes.
Rusting, gas bubbles, tarnishing, reacting with, cooking, decomposing, burning, etc.
Explain why making a solution is a physical change.
What is you are able to separate the ingredients by evaporating the water. Both ingredients remain the same chemically.
Gas to Liquid
What is condensation?
Ice to liquid. Explain why.
What is physical? A change of state is a physical change.
This law states that matter can never be created or destroyed in chemical reactions. The number of atoms before and after a reaction is equal.
What is the law of conservation of matter?
A nail was placed in each of two bottles-one with water, the other without. Compare what happened in both bottles.
What is the nail in the bottle with water rusted because the iron reacted with the oxygen and water to form rust?
Give 5 examples of physical properties.
What are color, texture, size, shape, state, solubility, etc.
Liquid to Gas
What is evaporation?
Making pancakes. Explain why.
The properties of the ingredients before and after they have been cooked are very different. The ingredients cannot be separated and cooking the batter is an irreversible change.
The amount of matter an object has.
What is mass?
How can you tell the difference between a chemical and physical change?
What is chemical changes result in the formation of a new substance?
Explain why tearing a piece of paper is a physical change.
The paper did not change on the molecular level. It is still paper.
Liquid to Solid
What is freezing?
Photosynthesis. Explain why.
What is chemical? The reactions within the plant cause changes at the molecular level.
A change that results in the formation of a new substance.
What is a chemical change?
Milk souring is an example of a chemical change. Explain why.
What is the milk smells bad because the bacteria in the milk have formed a new substance (lactic acid)?
Explain why mixing food coloring and water and is not a chemical change.
The pigment molecules from the food coloring dissolve into the water and cause the color change. This is a physical change. A new substance has not been produced, therefore it is not a chemical change.
Solid to Gas
What is sublimation?
Burning a candle and watching the wax melt.
What is BOTH? The burning part is chemical because a chemical reaction takes place with the oxygen and the wick. Ash, a new substance is formed. The melting part is physical because the wax is just changing state.