1. Chapter 2
Matter and Change

2. What is Chemistry
Chemistry is the study of the composition, structure, and properties of matter, the processes that matter undergoes, and the energy changes that accompany these processes.

3. What is everything made of?
What characteristics or properties make matter what it is?
What properties do all matter have in common?

4. What is Matter? Matter is anything that takes up space and has mass.
This is too much to handle
Needs to be broken down into categories and subcategories.

5. Matter Flowchart

6. Mixtures

7. Mixtures
Mixtures are a physical blending of two or more pure substances.
They have variable composition.
A Heterogeneous mixture is not uniform in composition, it has more than one phase.
Ex: Oil in water, Chocolate chip cookie, gravel, soil.

8. Mixtures A Homogeneous mixture is uniform throughout, a single phase.
Ex: Kool-aid, air, salt water.
Another name for homogenous mixture is solution.
Every part of the mixture keeps its own properties.

9. Pure Substances

10. Building Blocks of Matter
An element is a pure substance that cannot be broken down into simpler, stable substances and is made of one type of atom.
A compound is a substance that can be broken down into simpler, stable substances. Each compound is made from the atoms of two or more elements that are chemically bonded.

11. Pure Substances vs Mixtures
Have a fixed composition and differs from a mixture in the following ways:
All samples of a pure substance have the same characteristic physical and chemical properties.
Every sample of a given pure substance has exactly the same composition, such as all water molecules contain, 11.2% hydrogen, 88.8% oxygen.

12. Properties and Changes in Matter
Extensive Properties depends on the amount of matter that is present.
Ex:
Volume
Mass
Amount of energy in the substance

13. Properties and Changes in Matter
Intensive Properties do not depend on the amount of matter present.
Ex:
Melting point
Boiling point
Density
Ability to conduct electricity
Ability to transfer energy as heat

14. Properties
Physical Properties are properties that can be observed and measured without changing the substance.
cutting, grinding, dissolving, shrinking or expanding.

15. Properties
Chemical Properties are properties that can only be observed by changing the type of substance.
A chemical reaction takes place and new substances are produced.
Ability to sustain fire, flammability, can neutralize a base,

16. States of matter
Solid- matter that can not flow, has a definite shape and has definite volume.
Liquid- definite volume but takes the shape of its container (flows).
Gas- a substance without definite volume or shape and can flow.
Vapor- a substance that is currently a gas but normally is a liquid or solid at room temperature.

17. States of Matter Definite Volume? Definite Shape? Com-pressible? Solid
Expansion w/ Temp. increase
Com-pressible?
Small Expans.
Solid
YES
YES NO
Small Expans.
Liquid NO NO
YES
Large Expans.
Gas NO NO
YES

18. Condense
Freeze
Melt
Evaporate
Solid
Liquid
Gas

19. States of Matter There are more Plasma high temperature low pressure
electrons separate from nucleus
Most common in the universe
More at very low temp
Bose- Einstein condensate
Quantum superfluids

20. Another Way to Change States
Pressure
For some substances it will turn solids to liquids
Lake under Antarctica
For others it will turn liquids to solids
Silly putty
Dry Ice
Will turn gas to liquid
Compressor in refrigerator and AC

21. Physical Changes
A change that changes appearances, without changing the composition.
Examples?
Change of size
Change of state: solid  liquid  gas
Grinding

22. Chemical Changes
Chemical changes - a change where a new form of matter is formed.
Also called chemical reaction.
Reactant(s)  Product(s)
Not phase changes
Ice is still water.

23. Chemical Reactions
When one or more substances are changed into new substances.
Reactants- stuff you start with
Products- What you make
NEW PROPERTIES
Because each substance has its own properties

24. Indications of a chemical reaction
Temperature absorbed or released
Gas produced
Color change
Odor change
Precipitate- solid that separates from solution, cloudy appearance
Light emitted or absorbed
ONLY CLUES NOT CERTAINTY!

25. Chemical symbols There are 116 elements
Each has a 1 or two letter symbol
First letter always capitalized second never
Don’t need to memorize
Some from Latin or other languages

26. Chemical symbols Used to write chemical formulas
Subscripts tell us how many of each atom
H2O
C3H8
HBrO3

27. Periodic Table
Families or Groups – there are 18 vertical columns on the periodic table.
The elements in a group have similar chemical properties.
Periods – horizontal rows of elements in the periodic table.
There are 7 rows.

28. Periodic Table
Elements near each other tend to have similar characteristics and those farther apart are very different.
Example: Na and Mg are both metals that are very reactive. However, Na and Ar, a nobel gas, are very different from each other.

29. Types of Elements
Metals – an element that is a good conductor of electricity, a good heat conductor and has a metallic luster.
Most metals are:
solids at room temperature,
Malleable - hammered or rolled into thin sheets
Ductile - drawn into a fine wire
have high tensile strength - the ability to resist breakage when pulled.

30. Types of Elements
Non-metals – an element that is a poor conductor of heat and electricity.
Non-metals are:
Solids, liquids, or gases at room temperature.
Solids tend to be brittle
Low conductivity
Non-luminous (not shinny)

31. Types of Elements
Metalloids – is an element that has some of the characteristics of metals and some characteristics of non-metals.
Metalloids are:
Solids at room temperature
Less malleable than metals but not as brittle as non-metals
Have a somewhat metallic luster
Tend to be semiconductors of electricity
Used in solid state circuitry found in computers, digital watches, T.V., and radio.

32. Periodic Table of Elements
Most elements are metals and are located on the right side of the periodic table.
Non-metals are located on the left side of the table.
Metalloids separate metals from non-metals and are located on a diagonal.

33. Periodic Table of Elements

34. Naming Simple Compounds
There are several types of compounds.
metal / non-metal compounds
non-metal / non-metal compounds
There are several ways to name compounds.

35. Naming Simple Compounds
For metal / non-metal compounds
The first element is always a metal.
The metal element keeps the name it has from the periodic table.
NaCl: sodium -----
Mg3N magnesium ----

36. Naming Simple Compounds
The second element is always a non-metal.
The non-metal element changes the ending of it’s name to “ide”.
NaCl:
chlorine to chloride
sodium chloride
Mg3N2
nitrogen to nitride
magnesium nitride

37. Naming Simple Compounds
Try these:
KBr
SrO
RbF
Na2S
Ca3N2

38. Naming Simple Compounds
Try these:
KBr potassium bromide
SrO strontium oxide
RbF rubidium fluoride
Na2S sodium sulfide
Ca3N2 calcium nitride

39. Naming Simple Compounds
For non-metal / non-metal compounds
The elements are both non-metal.
The first non-metal element keeps the name it has from the periodic table (just like metals).
The second non-metal element changes the ending of it’s name to “ide”. (Just like metal / non-metal)

40. Naming Simple Compounds
Non-metal elements can make several compounds with the same two elements.
Ex:
NO2
N2O5
NO3
N2O3

41. Naming Simple Compounds
If we name all of these compounds like we do metal / non-metal they would all have the same name: nitrogen oxide.
To indicate how many of each atom is in the compound we use Greek prefixes before the elements name:
mono 1
di 2
tri 3

42. Naming Simple Compounds
tetra 4
penta 5
hexa 6
hepta 7
octa 8
nona 9
deca 10

43. Naming Simple Compounds
Ex:
NO2
first element: nitrogen (one)
second element: oxygen  oxide (two)
NAME: nitrogen dioxide
N2O5
first element: nitrogen (two)
second element: oxygen  oxide (five)
NAME: dinitrogen pentoxide

44. Naming Simple Compounds
Some things to note:
Never use “mono” with the first element!
Drop the vowel on the Greek prefix if the element begins with a vowel
CO is not carbon monooxide it is monoxide

45. Naming Simple Compounds
So now try these:
NO3
N2O3 OF
CCl4 CO
CO2