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.