Solids, Liquids, Gases Review

Solids, Liquids, Gases Review

Chemical Changes

• Occurs when a substance combines with another substance to create a new substance.

• Chemical properties occur during a chemical reaction.

Multiple Select

Which of the following is an example of a chemical change? Choose all that apply.

• Water freezing

• Sodium and chloride creating table salt

• Brownies baking in the oven

Physical Changesee

• Physical changes do not create a new substance.

• Physical properties are observable properties.

Multiple Select

Which of the following is an example of a physical property? Choose all that apply.

• Wood burning

• Chocolate melting

• Baking soda combining with vinegar

Mass

• The amount of matter in an object

• Scientists prefer to measure in mass because it is the same anywhere that we go.

Weight

• The amount that something weighs

• Varies between different locations

Open Ended

What is the difference between mass and weight?

Density

• A measure of how much matter occupies a given amount of space.

• The formula to determine density is: mass per unit volume.

• Density=mass/volume

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Volume

• The amount of space that matter takes up

• Typically measured in 3 units:

• Solids: m^3, cm^3, g

• Liquids: L, mL

Solids

• Has a definite shape and a definite volume

• The particles are packed very close together and only vibrate and sway slightly

Types of Solids

• Amorphous: Flexible, do not have a set pattern of molecules

• Crystalline: Hard and brittle, have a set pattern of molecules

Liquids

• Has a definite volume but no shape of its own

• Particles are in close contact with each other but they are not fixed in place

Surface Tension

• An inward force, among the molecules in a liquid that brings the molecules on a surface closer together.

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Viscosity

• Resistance to flowing

• Depends on the size and shape of the particles in a substance

• High viscosity: more resistant to flowing

• Low viscosity: flows quickly

Open Ended

Give an example of a substance with high viscosity and of a substance with low viscosity?

Gases

• Has neither a definite shape or volume

• The particles do not remain in contact and they move very quickly

Thermal Energy

• The total kinetic and potential energy of all the particles in a substance.

• Everything has thermal energy

Potential vs. Kinetic Energy

• Potential energy: Stored energy

• Kinetic energy: The energy of mass in motion

Temperature

• The average of the potential and kinetic energy in an object

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Heat

• High temperature

• Subjective

Open Ended

What is the difference between thermal energy and heat?