chapter 1 and 2 chem

Lemons taste sour is

a qualitative observation

Chemistry is often called the ________ science because it involves the study of the materials in the universe and the changes these materials undergo.

central

A ________ change alters the identity of the materials.

chemical

A heterogeneous mixture

has different types of particles and its composition is different in different regions.

Solid

A form of matter that has a definite shape and volume

Which of the following is another name for a scientific test?

An experiment

Which one of the following properties of phosphorus is a physical property?

Is a white, waxy solid

2 solutions mixed together and in time the solids sink to the bottom

Precipitate

A physical change

a phase change.

Gaseous nitrogen condenses to form a liquid is a ________ change and is a ________ property of nitrogen.

physical; physical

A successful chemistry student will

practice solving a lot of problems.

Which one of the following is not a hypothesis?

A car weighs 3,756 lb.

Which of the following is a possible explanation for a set of observations?

A hypothesis

liquid

A state of matter that has no definite shape but has a definite volume.

Gas

A state of matter with no definite shape or volume

Which of the following is a probable explanation for a set of observations or a set of tested hypotheses?

A theory

Which one of the following occupies a fixed volume and has a definite shape?

Marble

Of the following, which one is probably least helpful in being successful in this course?

Memorizing facts

Which one of the following household chores does not involve a chemical process?

Sweeping the floor

Chemistry deals with

both the nature of and the changes in materials

By definition, a mixture has variable

composition.

When baking a cake, the baking soda (NaHCO3), in the recipe is converted to sodium carbonate, carbon dioxide, and water. Baking soda is a(n) ________ and undergoes a ________ change during the baking process.

compound; chemical

The simplest pure substance is called ...

element

Chemistry is a(n) ________ science.

experimental

Distillation can be used to separate

homogeneous mixtures.

Chlorofluorocarbons (CFCs) are a type of industrial chemical. It was noted in the 1980s that as the production of CFCs increased, damage to the earth's ozone layer increased. With this information, classify the statement, "CFCs damage the ozone layer."

hypothesis

The scientific approach of critical thinking is useful in resolving many of our everyday problems. In proper order, critical thinking involves

observation, hypothesis, and experiment.

"What goes up must come down" is an example of a scientific

law

When a compound called an acid is mixed with a compound called a base, a reaction always occurs. Thus, the statement, "acids react with bases" is an example of a scientific

law

Melting is the process by which a solid becomes a

liquid

Matter is composed of atoms is an example of a scientific

model

Helium is

an element.

Chemistry is a science that is useful to everyone since it is used in many different occupational areas.

true

What do we call a test to gather more information to support or discredit a hypothesis?

An experiment

If you had a homogeneous mixture of ethyl alcohol and water, what method would you use to obtain pure ethyl alcohol?

Distillation

What is a common method for separating solids from liquids?

Filtration

chemical change

Gas formation odor Color change Transfer of energy heat sound light Formation of a solid

Which one of the following observations would demonstrate that a substance is a mixture?

It can be separated into simpler substances by physical methods.

Which one of the following properties of nitrogen is a chemical property?

It reacts with oxygen at high pressure

Which of the following is not a physical property?

Water reacts with sodium metal

Which one of the following cannot be broken down into simpler substances by chemical means?

Xenon, Xe

Peanuts and popcorn form

a heterogeneous mixture.

A quantitative observation is known as

a measurement.

Some large cars get 3.2 fewer miles per gallon than some small cars is

a quantitative observation.

The state of matter that has a definite volume and rigid shape is called

a solid.