Phases of Matter
Phase Changes
Phase Change Graphs
Independent vs. Dependent Variables
Phases of Matter Molecular Energy
100
What are the three main phases of matter?
Solid, Liquid and Gas (and Plasma)
100
What is the process called when a solid turns into a liquid?
Melting
100
What does a phase change graph show?
A phase change graph shows the changes in state of a substance as it is heated or cooled, illustrating temperature vs. time or energy.
100
What is an independent variable?
An independent variable is the factor that is changed or manipulated in an experiment. On the x-axis.
100
How does the energy of particles in a solid compare to that of particles in a gas?
The energy of particles in a solid is lower than that of particles in a gas, as solid particles vibrate in place while gas particles move freely with higher energy.
200
Describe the arrangement of particles in a solid.
In a solid, particles are closely packed together in a fixed arrangement and vibrate in place.
200
What phase change occurs when a liquid becomes a gas?
Vaporization
200
What does the flat part of a phase change graph represent?
The flat part of a phase change graph represents a phase change, where the temperature remains constant while the substance transitions between states.
200
What is a dependent variable?
A dependent variable is the factor that is measured or observed in response to the changes in the independent variable.On the y-axis.
200
What happens to molecular energy when a substance is heated?
When a substance is heated, its molecular energy increases, causing the particles to move faster.
300
What phase of matter has a definite shape and volume?
Solid
300
Describe what happens during freezing.
During freezing, the particles in a liquid lose energy and move closer together, forming a solid.
300
In a phase change graph, what does a rising line indicate?
A rising line in a phase change graph indicates that the temperature of the substance is increasing as heat is being added.
300
In an experiment to test the effect of temperature on the time it takes for ice to melt, what would be the independent variable?
The temperature
300
Explain how temperature affects molecular motion
As temperature increases, molecular motion increases, resulting in faster particle movement and greater energy.
400
All phases of matter have ________ and ________
Mass and shape
400
What is condensation? Give an example.
Condensation is the process where a gas turns into a liquid; an example is water droplets forming on a cold glass.
400
Is this substamce water?
Yes.
400
Why is it important to control some variables in an experiment?
To make sure the effects of the independent variable can be accurately measured.
400
Why do gases have more energy than liquids?
Gases have more energy than liquids because gas particles are in constant, rapid motion and are far apart, while liquid particles are closer together and move more slowly.
500
What happens to the particles in a gas compared to a liquid?
In a gas, particles are much farther apart and move freely compared to a liquid, where particles are closer together but can slide past one another.
500
Explain what happens during sublimation.
During sublimation, a solid turns directly into a gas without becoming a liquid, such as dry ice turning into carbon dioxide gas.
500
If a substance has a melting point of 20oC and a Boiling point of 110oC, is the substance water?
No.
500
Provide an example of an experiment that includes both an independent and a dependent variable.
An example of an experiment with both variables could be testing how different amounts of sunlight (independent variable) affect the growth of a plant (dependent variable).
500
Describe how energy changes during a chemical reaction that absorbs heat.
During a chemical reaction that absorbs heat (endothermic reaction), energy is taken in from the surroundings, resulting in lower energy products compared to the reactants.