1. Composition, Structure, and Behavior
Chemistry and Matter: Basic Concepts
Topic 1
Composition, Structure, and Behavior
is the science that investigates and explains the structure and properties of matter.
is the stuff that’s all around you: the metal and plastic of a telephone, the paper and ink of a book. . . Everything
A more formal definition of matter is anything that takes up space and has mass.

2. 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 of matter describe the characteristics and behavior of matter, including the changes that matter undergoes.

3. 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 type of classification.
When you examine an unknown piece of stuff, you first ask, “ ?”
Sucrose is composed of the elements carbon, hydrogen, and oxygen.

4. 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 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 pure substance is matter, either an element or compound, with the same fixed composition and properties.

5. 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 individual properties.
Ocean H2O is an example of a mixture

6. Chemistry and Matter: Basic Concepts
Topic 1

7. Elements (Pure Substance)
Simplest form of matter
Pure chemical substance consisting of one form of matter
Can’t be broken down into simpler substances without changing its identity.
Tungsten (W)
Neon (Ne)
Copper (Cu)

8. Compounds (Pure Substance)
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.

9. e.g.: NaCl, H2O, CO2
The properties of the compound are different from the properties of the elements that compose the compound.

10. Mixtures (NOT a pure substance)
Two types:
homogeneous
Heterogeneous
Definition: 2 or more different substances that are not easily combined. These can be separated and retain their identity.

11. Mixtures
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.

12. Mixtures
Homogeneous mixtures are the same throughout.

13. Another name for this type of 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.

14. 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, and contact-lens cleaner
In addition, most of the processes of life occur in aqueous solutions.
Solute: thing being dissolved
Solvent: liquid the solute is dissolved in

15. Alloy
Alloys are solid solutions that contain different metals and sometimes nonmetallic substances.
E.g.: steel is an alloy containing iron and carbon
18 karat gold is 75% gold (Au), 25% copper (Cu).

16. Emulsion
Mixture of two or more liquids which are normally immiscible (not mixable)
Examples:

17. 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.

18. One type of pure substance can be broken down into simpler substances
One type of pure substance can be broken down into simpler substances. This type of substance is called a .
Another type of substance cannot be broken down into simpler substances. Such a substance is called an .
All the substances of the universe are either elements, compounds formed from elements, or of elements and compounds.

19. Of the known elements, only about 90 occur naturally on Earth
Of the known elements, only about 90 occur naturally on Earth. The remainder are , 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.

20. Pure substance or a mixture?
Chemistry and Matter: Basic Concepts
Topic 1
Pure substance or a mixture?
A 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,
dissolving,
melting,
and crystallizing.

21. 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.

22. 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,
boiling point,
color,
electrical conductivity,
and physical state (solid, liquid, or gas).

23. 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.

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

25. 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 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.

26. 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.

27. 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 that compose the compound.
silver bromine = silver bromide

28. Compounds Are More Than One Element
Chemistry and Matter: Basic Concepts
Topic 1
Compounds Are More Than One Element
A 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

29. 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.

30. 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 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 on a cool surface to form liquid water.

31. 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.

32. 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.

33. 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.

34. 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.

35. Chemical Changes Topic 1 Chemistry and Matter: Basic Concepts
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36. 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.

37. 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.

38. 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.

39. 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.

40. 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.

41. 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.