Classification, Properties, and Changes of Matter

50 Question and Answer flashcards reviewing the classification, properties, and changes of matter based on student lecture notes.

What does the prefix "hetero-" mean in a heterogeneous mixture?

Different

What does the prefix "homo-" mean in a homogeneous mixture?

Same

How are the parts of a homogeneous mixture distributed?

They are evenly distributed.

How easy is it to identify one substance from another in a homogeneous mixture?

It is hard to identify one substance from another.

What is a solution?

A well-mixed homogeneous mixture that contains a solvent and at least one solute.

What size are the particles in a solution?

Small

What can be said about the properties throughout a solution?

It has the same properties throughout.

What is a colloid?

A heterogeneous mixture containing small, undissolved particles that do not settle out.

How do particle sizes in colloids compare to solutions, and what effect do they have on light?

They have larger particles than a solution, which are enough to scatter light.

What is a suspension?

A heterogeneous mixture in which large particles can be seen and easily separated.

What appearance is typical for a suspension?

Typically cloudy.

Why is separating mixtures usually easy?

Because components keep their own properties.

What four methods for separating mixtures are listed in the notes?

Magnetic attraction, filtration, distillation, and evaporation.

In the classification chart, what question determines if matter is a mixture or a pure substance?

Separated by Physical Means?

What element example is provided in the classification chart?

Uranium

What compound example is provided in the classification chart?

$$CO_2$$

What example of a homogeneous mixture (solution) is provided in the classification chart?

Stainless Steel

What two examples of colloids are given in the notes?

Ice cream and milk.

What three examples of suspensions are given in the classification chart?

Sand, cereal, and dirt.

How is matter defined in the notes?

Anything that has mass and takes up space.

Why do different materials have different properties?

Because they have different compositions.

What is a pure substance?

Matter that has a specific composition where physical and chemical properties do not vary.

How are molecules formed?

Formed when atoms combine.

What is a compound?

A substance containing 2 or more elements joined in fixed proportions that are chemically combined.

How may a compound be represented?

By a chemical formula.

How do the properties of a compound compare to the properties of the substances that make it up?

The properties of a compound can differ from the properties of substances that make up a compound.

What is a mixture?

A combination of substances, held together but not chemically combined.

What happens to the individual properties of substances in a mixture?

Each substance keeps individual properties.

Are the parts of a mixture combined in a set ratio?

No, parts of a mixture are not combined in a set ratio.

What are physical properties?

Characteristics of a material that do not change it into another substance.

What are two uses of physical properties mentioned in the notes?

Used to identify material and choose material for a specific purpose.

What is mass?

Amount of matter in an object.

What is hardness?

A material's ability to resist scratching.

What is the melting point of a substance?

The temperature at which a substance changes from solid to liquid.

What is the boiling point of a substance?

The temperature at which a substance changes from liquid to gas.

What is volume?

Amount of space matter takes up.

What is density?

Measure of how much mass is contained in a given volume.

How is density used according to the physical properties notes?

It is used to help identify a substance.

What is viscosity?

Tendency of a liquid to keep from flowing.

What is conductivity?

A material's ability to allow heat to flow.

What is malleability?

Ability of a solid to be hammered without shattering.

When does a physical change occur?

Occurs when some of the material's properties change, but substance in materials stays the same.

What three types of changes characterize a physical change?

Changes in shape, state, or form.

Can physical changes be reversed?

Some physical changes can be reversed, others cannot.

What is a chemical property?

An ability to produce a change in the composition of matter.

What is flammability?

A material's ability to burn in the presence of oxygen.

What is reactivity?

How readily a substance combines chemically with another substance.

When does a chemical change occur?

When substances combine or break apart chemically to form a new substance.

What does the Law of Conservation of Mass state?

Matter is not destroyed or created in any change.

What are five clues to look for that indicate a chemical change?

Change in color, production of gas, formation of precipitate, production of odor, and substance "disappears".