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

3. 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. 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. 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. 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. 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. aspirin 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.

9. 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. 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. 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. 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. Chemistry and Matter: Basic Concepts Topic 1 Pure substance or a mixture? • A substance is matter, either an element or compound, with the same fixed composition and properties.

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

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

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

27. 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 physicalproperties. • More than 10 million compounds are known and the number keeps growing.

28. 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. silver + bromine = silver bromide 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.

30. 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. 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.

32. 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. 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. 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. 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 chemical change, the change of one or more substances into other substances. Chemistry and Matter: Basic Concepts Topic 1 Chemical Changes • Another term for chemical change is chemical reaction.

38. Chemistry and Matter: Basic Concepts Topic 1 Chemical Changes Click box to view movie clip.

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. 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. 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. 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 exothermicreactions. • Chemical reactions that absorb heat energy are called endothermic reactions.

43. 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. Chemistry and Matter: Basic Concepts Topic 1 Chemical Reactions and Energy

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

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

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

50. Chemistry and Matter: Additional Concepts Topic 1 Branches of Chemistry