1. Topic 1

2. Topic 1: Chemistry and Matter
Table of Contents
Topic 1
Topic 1: Chemistry and Matter
Basic Concepts
Additional Concepts

3. Composition, Structure, and Behavior
Chemistry and Matter: Basic Concepts
Topic 1
Composition, Structure, and Behavior
Chemistry is the science that investigates and explains the structure and properties of matter.
Matter is the stuff that’s all around you: the metal and plastic of a telephone, the paper and ink of a book, the glass and liquid of a bottle of soda, the air you breathe, and the materials that make up your body.
A more formal definition of matter is anything that takes up space and has mass.

4. Composition, Structure, and Behavior
Chemistry and Matter: Basic Concepts
Topic 1
Composition, Structure, and Behavior
Mass is the measure of the amount of matter that an object contains.
The structure of matter refers to its composition—what matter is made of—as well as how matter is organized.
The properties of matter describe the characteristics and behavior of matter, including the changes that matter undergoes.

5. Macroscopic View of Matter
Chemistry and Matter: Basic Concepts
Topic 1
Macroscopic View of Matter
Matter that is large enough to be seen is called macroscopic, so all of your observations in chemistry, and everywhere else, start from this perspective.
You may get hints of the actual structure from a macroscopic view. You must go to a submicroscopic perspective to understand how the hidden structure of matter influences its behavior.

6. Submicroscopic View of Matter
Chemistry and Matter: Basic Concepts
Topic 1
Submicroscopic View of Matter
The submicroscopic view gives you a glimpse into the world of atoms.
It is a world so small that you cannot see it even with the most powerful microscope, hence the term submicroscopic.
You learned in earlier science courses that matter is made up of atoms.

7. Using Models in Chemistry
Chemistry and Matter: Basic Concepts
Topic 1
Using Models in Chemistry
In your study of chemistry, you will use both macroscopic and submicroscopic perspectives.
For example, sucrose and aspirin are both composed of carbon, hydrogen, and oxygen atoms, but they have different behaviors and functions.
These differences must come about because of differences in the submicroscopic arrangement of their atoms.

8. Comparing the Structures of Aspirin and Sucrose
Chemistry and Matter: Basic Concepts
Topic 1
Comparing the Structures of Aspirin and Sucrose
The different submicroscopic arrangements of the atoms in aspirin and sucrose cause the differences in their behavior.
aspirin
sucrose

9. Using Models in Chemistry
Chemistry and Matter: Basic Concepts
Topic 1
Using Models in Chemistry
A scientific model is a thinking device that helps you understand and explain macroscopic observations. Scientific models are built on experimentation.

10. Classification by Composition
Chemistry and Matter: Basic Concepts
Topic 1
Classification by Composition
A powerful way to classify matter is by its composition. This is the broadest type of classification.
When you examine an unknown piece of stuff, you first ask, “What is it made of?”
Sucrose is composed of the elements carbon, hydrogen, and oxygen. This is a qualitative expression of composition.
A qualitative observation is one that can be made without measurement.

11. Classification by Composition
Chemistry and Matter: Basic Concepts
Topic 1
Classification by Composition
After a qualitative analysis, the next question that you might ask is how much of each of the elements is present.
For sucrose, the answer to that question is that 100 g of sucrose contains 42.1 g of carbon, 51.4 g of oxygen, and 6.5 g of hydrogen. This is a quantitative expression of composition.
A quantitative observation is one that uses measurement.

12. Pure substance or a mixture?
Chemistry and Matter: Basic Concepts
Topic 1
Pure substance or a mixture?
A sample of matter is either pure—made up of
only one kind of matter— or it is a mixture of different kinds of matter.
A substance is matter, either an element or compound, with the same fixed composition and properties.

13. Pure substance or a mixture?
Chemistry and Matter: Basic Concepts
Topic 1
Pure substance or a mixture?
A mixture is a combination of two or more substances in which the basic identity of each
substance is not changed.
Unlike pure substances, mixtures do not have specific compositions.

14. Pure substance or a mixture?
Chemistry and Matter: Basic Concepts
Topic 1
Pure substance or a mixture?
A physical change is a change in matter that does not involve a change in the chemical identity of individual substances.
Examples of physical changes include:
boiling,
evaporating,
freezing,
dissolving,
melting,
and crystallizing.

15. Pure substance or a mixture?
Chemistry and Matter: Basic Concepts
Topic 1
Pure substance or a mixture?
Physical properties are characteristics that a sample of matter exhibits without any change in its identity.

16. Pure substance or a mixture?
Chemistry and Matter: Basic Concepts
Topic 1
Pure substance or a mixture?
Examples of the physical properties of a chunk of matter include its:
solubility,
melting point,
boiling point,
color,
density,
electrical conductivity,
and physical state (solid, liquid, or gas).

17. Pure substance or a mixture?
Chemistry and Matter: Basic Concepts
Topic 1
Pure substance or a mixture?
A heterogeneous mixture is one with different compositions, depending upon where you look.
The components of the mixture exist as distinct regions, often called phases.

18. Pure substance or a mixture?
Chemistry and Matter: Basic Concepts
Topic 1
Pure substance or a mixture?
Homogeneous mixtures are the same throughout.
Another name for a homogeneous mixture is solution.
Some solutions are gases. Air, for example, is a homogeneous mixture of several gases.
Some solutions are solid.
Liquid solutions do not have to be liquid or contain water.

19. Pure substance or a mixture?
Chemistry and Matter: Basic Concepts
Topic 1
Pure substance or a mixture?
Alloys are solid solutions that contain different metals and sometimes nonmetallic substances.

20. Pure substance or a mixture?
Chemistry and Matter: Basic Concepts
Topic 1
Pure substance or a mixture?
When you dissolve sugar in water, sugar is the solute—the substance being dissolved.
The substance that dissolves the solute, in this case water, is the solvent.
When the solvent is water, the solution is called an aqueous solution.

21. Pure substance or a mixture?
Chemistry and Matter: Basic Concepts
Topic 1
Pure substance or a mixture?
Many of the solutions you encounter are aqueous solutions, for example, soda, tea, contact-lens cleaner, and other clear cleaning liquids.
In addition, most of the processes of life occur in aqueous solutions.

22. Pure substance or a mixture?
Chemistry and Matter: Basic Concepts
Topic 1
Pure substance or a mixture?

23. Two Types of Substances
Chemistry and Matter: Basic Concepts
Topic 1
Two Types of Substances
One type of pure substance can be broken down into simpler substances. This type of substance is called a compound.
Another type of substance cannot be broken down into simpler substances. Such a substance is called an element.
All the substances of the universe are either elements, compounds formed from elements, or mixtures of elements and compounds.

24. Two Types of Substances
Chemistry and Matter: Basic Concepts
Topic 1
Two Types of Substances
Of the known elements, only about 90 occur naturally on Earth. The remainder are synthesized, usually in barely detectable amounts, in high-energy nuclear experiments.
Less than half of the 90 naturally occurring elements are abundant enough to play a significant role in the chemistry of everyday stuff.

25. Organizing the Elements
Chemistry and Matter: Basic Concepts
Topic 1
Organizing the Elements
The periodic table organizes elements in a way that provides a wealth of chemical information—much more than is evident to you now. It shows the chemical symbols for the elements.
Their symbols usually correspond to their names in Latin.

26. Periodic Table of the Elements
Chemistry and Matter: Basic Concepts
Topic 1
Periodic Table of the Elements

27. Compounds Are More Than One Element
Chemistry and Matter: Basic Concepts
Topic 1
Compounds Are More Than One Element
A more complete definition is that a compound is a chemical combination of two or more different elements joined together in a fixed proportion with a unique set of chemical and physical properties.
More than 10 million compounds are known and the number keeps growing.

28. Compounds Are More Than One Element
Chemistry and Matter: Basic Concepts
Topic 1
Compounds Are More Than One Element
Some new compounds are discovered and isolated from natural chemical sources such as plants and colonies of bacteria and are synthesized in laboratories for many different uses.

29. Compounds Are More Than One Element
Chemistry and Matter: Basic Concepts
Topic 1
Compounds Are More Than One Element
The properties of the compound are different from the properties of the elements that compose the compound.
silver bromine = silver bromide

30. Compounds Are More Than One Element
Chemistry and Matter: Basic Concepts
Topic 1
Compounds Are More Than One Element
More than 10 million compounds are known and the number keeps growing.
New compounds are discovered and isolated from natural chemical sources such as plants and colonies of bacteria and are synthesized in laboratories for many different uses.

31. Compounds Are More Than One Element
Chemistry and Matter: Basic Concepts
Topic 1
Compounds Are More Than One Element
A formula is a combination of the chemical symbols that show what elements make up a compound and the number of atoms of each element.
Compound
Formula
Caffeine
C8H10N4O2

32. Compounds Are More Than One Element
Chemistry and Matter: Basic Concepts
Topic 1
Compounds Are More Than One Element
Formulas provide a shorthand way of describing a submicroscopic view of a compound.
You probably already use formulas like H2O and CO2 as a way of talking about water and carbon dioxide.

33. Chemistry and Matter: Basic Concepts
Topic 1
States of Matter
Most matter on Earth exists in one of three physical states: solid, liquid, or gas. A fourth state of matter, called plasma, is less familiar.
Changes in state are examples of physical changes because there is no change in the chemical composition identity of the substance.
Ice can melt back to form liquid water, and steam will condense on a cool surface to form liquid water.

34. Alcohol and gasoline are more volatile than water.
Chemistry and Matter: Basic Concepts
Topic 1
States of Matter
Some substances are described as volatile, which means that they change to a gas easily at room temperature.
Alcohol and gasoline are more volatile than water.
Density is the amount of matter (mass) contained in a unit of volume.
Styrofoam has a low density or small mass per unit of volume.

35. Stones have a large density or a large mass per unit of volume.
Chemistry and Matter: Basic Concepts
Topic 1
States of Matter
Stones have a large density or a large mass per unit of volume.
In science, the density of solids and liquids is usually measured in units of grams (mass) per milliliter (volume) or g/mL.

36. Inability to react is also a chemical property.
Chemistry and Matter: Basic Concepts
Topic 1
Chemical Properties
Chemical properties are those that can be observed only when there is a change in the composition of the substance.
Rusting is a chemical reaction in which iron combines with oxygen to form a new substance, iron oxide.
Inability to react is also a chemical property.

37. A chemical property always relates to a
Chemistry and Matter: Basic Concepts
Topic 1
Chemical Changes
chemical change, the change of one or more substances into other substances.
A chemical property always relates to a
Another term for chemical change is chemical reaction.

38. Chemical Changes Topic 1 Chemistry and Matter: Basic Concepts
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39. Chemistry and Matter: Basic Concepts
Topic 1
Chemical Changes
All matter is made of atoms, and any chemical change involves only a rearrangement of the atoms. Atoms do not just appear. Atoms do not just disappear.
This is an example of the law of conservation of mass, which says that in a chemical change, matter is neither created nor destroyed. It would be equally correct to call this the law of conservation of matter.

40. Chemical Reactions and Energy
Chemistry and Matter: Basic Concepts
Topic 1
Chemical Reactions and Energy
All chemical changes also involve some sort of energy change.
Energy is either taken in or given off as the chemical change takes place. Energy is the capacity to do work.
Work is done whenever something is moved.

41. Chemical Reactions and Energy
Chemistry and Matter: Basic Concepts
Topic 1
Chemical Reactions and Energy
Many reactions give off energy.
For example, burning wood is a chemical change in which cellulose, and other substances in the wood, combine with oxygen from the air to produce mainly carbon dioxide and water.

42. Chemical Reactions and Energy
Chemistry and Matter: Basic Concepts
Topic 1
Chemical Reactions and Energy
Energy is also produced and released in the form of heat and light.
Chemical reactions that give off heat energy are called exothermic reactions.
Chemical reactions that absorb heat energy are called endothermic reactions.

43. Chemical Reactions and Energy
Chemistry and Matter: Basic Concepts
Topic 1
Chemical Reactions and Energy
You can tell that the decomposition of water into oxygen and hydrogen is an endothermic reaction because it doesn’t occur unless energy, in the form
of an electric current, is passed through water.

44. Chemical Reactions and Energy
Chemistry and Matter: Basic Concepts
Topic 1
Chemical Reactions and Energy
Photosynthesis is probably the most important endothermic process on Earth.
Green plants, algae, and many kinds of bacteria carry out photosynthesis.

45. Basic Assessment Questions
Topic 1
Question 1
Identify each of the following as either a compound or a mixture.
A. sand
B. water
C. juice

46. Answers A. sand mixture B. water compound C. juice mixture Topic 1
Basic Assessment Questions
Topic 1
Answers
A. sand
mixture
B. water
compound
C. juice
mixture

47. Basic Assessment Questions
Topic 1
Question 2
Classify each of the following as a chemical or physical property.
A. density
B. reactivity
C. color
D. melting point

48. Answers A. density physical property B. reactivity chemical property
Basic Assessment Questions
Topic 1
Answers
A. density
physical property
B. reactivity
chemical property
C. color
physical property
D. melting point
physical property

49. Chemistry and Matter: Additional Concepts
Topic 1
Additional Concepts

50. Branches of Chemistry Topic 1
Chemistry and Matter: Additional Concepts
Topic 1
Branches of Chemistry
Branch
Area of Emphasis
Examples
Organic chemistry
most carbon-containing chemicals
pharmaceuticals, plastics
Inorganic chemistry
in general, matter that does not contain carbon
minerals, metals and nonmetals, semi-conductors
Physical chemistry
the behavior and changes of matter and the related energy changes
reaction rates, reaction mechanisms
Analytical chemistry
components and composition of substances
food nutrients, quality control
Biochemistry
matter and processes of living organisms
metabolism, fermentation

51. It is both an organized way for scientists to do
Chemistry and Matter: Additional Concepts
Topic 1
Scientific Methods
A scientific method is a systematic approach to answer a question or study a situation.
It is both an organized way for scientists to do
research and a way for scientists to verify the work of other scientists.

52. A typical scientific method includes:
Chemistry and Matter: Additional Concepts
Topic 1
Scientific Methods
A typical scientific method includes:
making observations,
forming a hypothesis,
performing an experiment,
and arriving at a conclusion.

53. Chemists also use numerical quantitative data.
Chemistry and Matter: Additional Concepts
Topic 1
Scientific Methods
Often, a scientist will begin with qualitative data—information that describes color, odor, shape, or some other physical characteristic that relates to the five senses.
Chemists also use numerical quantitative data.
A hypothesis is a possible explanation for what has been observed.
An experiment is a set of controlled observations that test a hypothesis.

54. Chemistry and Matter: Additional Concepts
Topic 1
Scientific Methods
The variable that is changed in an experiment is called the independent variable.
The variable that you watch to see how it changes as a result of your changes to the independent variable is called the dependent variable.

55. Chemistry and Matter: Additional Concepts
Topic 1
Scientific Methods
Many experiments also include a control, which is a standard for comparison.
A conclusion is a judgment based on the data obtained in the experiment.
If data support a hypothesis, the hypothesis is tentatively affirmed. Hypotheses are never proven; they are always subject to additional research.

56. Chemistry and Matter: Additional Concepts
Topic 1
Scientific Methods
Over time, data from many experiments can be used to form a visual, verbal, and/or mathematical explanation—called a model—of the phenomenon being studied.
A theory is an explanation that has been supported by many experiments.
Theories are always subject to new experimental data and are modified to include new data.

57. Chemistry and Matter: Additional Concepts
Topic 1
Scientific Methods
A scientific law describes a relationship in nature that is supported by many experiments and for which no exception has been found.

58. Applied research is undertaken to solve a specific problem.
Chemistry and Matter: Additional Concepts
Topic 1
Scientific Research
Pure research is done to gain knowledge for the sake of knowledge itself.
Applied research is undertaken to solve a specific problem.

59. Additional Assessment Questions
Topic 1
Question 1
Identify the dependent variable and the independent variable in the following experiments.

60. Additional Assessment Questions
Topic 1
Question 1a
A student tests the ability of a given chemical to dissolve in water at three different temperatures.
Answer 1a
independent variable: temperature;
dependent variable: ability to dissolve in water

61. Additional Assessment Questions
Topic 1
Question 1b
A farmer compares how his crops grow with and without phosphorous fertilizers.
Answer 1b
independent variable: presence of phosphorous fertilizer;
dependent variable: crop growth

62. Question 2 Classify each kind of research as either pure or applied.
Additional Assessment Questions
Topic 1
Question 2
Classify each kind of research as either pure or applied.

63. Additional Assessment Questions
Topic 1
Question 2a
A scientist studies plants in a rain forest in search of chemicals that might be used to treat AIDS.
Answer 2a
applied

64. Additional Assessment Questions
Topic 1
Question 2b
A researcher studies the effects of hormones on the brain of a worm.
Answer 2b
pure

65. Additional Assessment Questions
Topic 1
Question 2c
A researcher tries to develop cleaner burning fuels to help reduce air pollution.
Answer 2c
applied

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