Phase (Changes)
What phase change describes when a solid goes to a liquid?
Melting
Is baking a cake a chemical reaction?
Yes
Is a metal's ability to rust an example of a physical property?
No
Which way does heat always transfer?
From a high temperature object to a low temperature object.
What do humans do with the oxygen we breathe in?
We use oxygen to break down food for energy.
Which phase change describes when a gas goes to a liquid?
Condensation
When you burn a piece of paper, does all of the paper’s matter still exist, even though it has been changed into a different form?
Yes, because the paper’s matter becomes a gas!
Are solids always denser than liquids? Explain.
No, because ice (solid) floats in water (a liquid).
Heat transfer between two objects will continue until...
the two objects reach the same temperature.
What does the law of conservation of mass state?
Matter cannot be created nor destroyed.
Which phase has the most kinetic energy?
Gas
Give one example of a chemical property.
Rusting, reaction with HCl, flammability, combustion
Give one example of a physical property.
Color, Density, Luster, Conductivity, Texture,
You have two cups of soup touching each other. There will be no heat transfer between them if...
they are the exact same temperature.
What is air mostly made of?
(What makes up the majority of air?)
Nitrogen
Describe what happens to the kinetic energy when a substance goes from a liquid to a gas.
The kinetic energy increases.
Why is water freezing not an example of a chemical reaction?
The chemical formula (H20) does not change.
Fill in the blanks:
Solid: Keeps its ___________ and _______
Liquid: Takes on the shape of the __________________ and can ______
Gas: ___________ the entire container and can ________
Solid: Keeps its shape and volume.
Liquid: Takes on the shape of the bottom of the container and can flow.
Gas: Fill the entire container and can flow.
Fill in the blank:
Heat is the transfer of______ _____ from one object to another.
Heat is the transfer of kinetic energy from one object to another.
Explain what (heat transfer) happens when you fry an egg?
Heat transfers from the pan to the egg.
Which phase change describes when a substance goes from a gas to a solid.
Deposition
Give 5 pieces of evidence for a chemical reaction.
Light, formation of gas, formation of a solid, color change, temperature change.
Why should you not use mass, size, and shape to identify an object?
Mass, size, and shape can all be easily altered and / or many objects share the same qualities.
Students often complain that my classroom “makes them cold.” Explain how their bodies become cold.
Their bodies become cold because heat energy is flowing AWAY FROM their bodies and INTO their chair, the air, etc.
Solid to a gas describes which phase change?
Sublimation