1. Chem EOG review

2. 3 classifications of matter
Elements, compounds, mixtures

3. Element: made of one kind of atom Ex: Cu, O2, N2 Compound:
Made of two or more different elements chemically bonded (by electrons)
Have a fixed ratio of elements H2O 2:1 ratio H2O2 2:2 ratio
Compounds have different properties than the elements that make them.
H is a gas at room temp, and very reactive. O is a gas at room temp,
somewhat reactive. H2O is a liquid at room temp, not reactive
Can only be broken down into elements by a chemical reaction.
Mixture:
Two or more different substances that are physically combined, NO CHEMICAL BONDING
Can be homogeneous or heterogeneous
Homogeneous (same throughout, solid/liquid/gas…ex: air, salt water, brass)
Heterogeneous (different throughout…pizza, muddy water)
Can be easily separated into parts by physical methods (evaporation, sifting, magnetism, filtering)
Often retains the properties of its components

4. Elements
Pure substance that cannot be separated into simpler substance by physical or chemical means.

5. Atom: basic unit of matter Element: a type of atom that is defined by its atomic number: atomic number = number of protons

6. Subatomic particles
Proton + : large, positive charge Found in the nucleus Identity number Neutron 0 : large, neutral (no charge) Electron - : small, negative charge Outside nucleus in electron cloud Determines bonding

7. Number of protons
Number of electrons
Number of protons + neutrons
Doesn't’t include electrons because
they weigh next to nothing
TRY IT

8. Number of protons
Number of electrons 42
96-42=54 neutrons
Number of protons + neutrons
Doesn't’t include electrons because
they weigh next to nothing
Round the mass – atomic number = neutrons
TRY IT

9. Atom Identity!! TRY IT
Number of Proton, Neutron, Electrons in Ca Xe Te Using the atomic number, identify the following

10. Compounds
H2O
NaCl
Pure substance composed of two or more different elements joined by chemical bonds.
Made of elements in a specific ratio that is always the same
Has a chemical formula
Can only be separated by chemical reaction, not physically
CO2

11. Compounds or molecules are represented using a chemical formula
Subscripts (little number) tell you the number of atoms in the 1 molecule of the compound
Coefficients (big number out front) tell you how many molecules
(no number means the number is 1!)

12. Mixtures
A combination of two or more pure substances that are not chemically combined.
substances held together by physical forces, not chemical
No chemical change takes place
Each item retains its properties in the mixture
They can be separated physically
Chem4kids.com

13. Can you identify the following?
You will be shown a series of photos. Tell if each photo represents an item composed of an element, compound, or mixture. Ask Yourself…
Pure substance? yes then it’s an element or compound
one type of element: element
two or more different of elements: compound
Pure substance? no then it’s a mixture
homogeneous: looks and behaves like one material, components evenly dispersed and indistinguishable
heterogeneous: components unevenly dispersed and distinguishable

14. Element, Compound, or Mixture?
Rocks

15. Element, Compound, or Mixture?
Rocks

16. Element, Compound, or Mixture?
Copper

17. Element, Compound, or Mixture?
Copper Cu

18. Element, Compound, or Mixture?
Jelly Beans

19. Element, Compound, or Mixture?
Jelly Beans

20. Element, Compound, or Mixture?
Table Sugar

21. Element, Compound, or Mixture?
Table Sugar
C12H22O11

22. Element, Compound, or Mixture?
Diamond

23. Element, Compound, or Mixture?
Diamond C

24. Element, Compound, or Mixture?
Salt

25. Element, Compound, or Mixture?
NaCl
Salt

26. Element, Compound, or Mixture?
Neon Gas

27. Element, Compound, or Mixture?Ne
Neon Gas

28. Element, Compound, or Mixture?
Salad

29. Element, Compound, or Mixture?
Salad

30. Pure Substance?

31. Compound pure substance: every component is the same

32. Pure Substance?

33. Mixture

34. Pure Substance?

35. Element

36. Practice questions

37. Practice questions

39. Homogeneous mixture (solution)
Element

41. Carbon (C) and Hydrogen (H)

47. Metals Conduct heat Conduct electricity Malleable Ductile Shiny
Form + ions
Iron, sodium, aluminum, gold

48. Metalloids Found along the zig zag line
Have properties similar to both metals and non metals
Used in semiconductors
Silicon (Si)

49. Nonmetals Insulators (Do not conduct heat or electricity) Brittle
Dull in appearance
Form – ions
Chlorine, bromine, neon, oxygen
Many are gases at room temperature

50. Groups A group, also called family, is a vertical column in the periodic table of the elements. Groups are considered the most important way of classifying the elements. Elements within the same group have the same number of valence electrons, which is why they have similar chemical reactivities.

51. Periods A period is a horizontal row in the periodic table of the elements. The period number is equals the number of electron energy levels (rings) in the element.

52. Metal families
Alkali Group 1 extremely reactive, 1 valence electron Alkaline Earth Group 2 also very reactive, 2 valence electrons Transition metals groups 3-12 not very reactive, used more commonly in industry ex: gold, silver, iron

53. Nonmetal families
Halogens group 17 extremely reactive 7 valence electrons used in cleaning agents Ex: chlorine (Cl) Noble Gases group 18 Inert: do not bond to form molecules or compounds 8 valence electrons (full) Exist as single atoms because they are stable.

54. Octet Rule (8)
Atoms bond with other atoms to complete their valence (outer) ring of electrons to become stable. Full valence rings: (2,8,8) Ionic bond: transfers electrons (groups 1, 2, 17) Covalent bond: share electrons common 1-to-1 bonding: Alkali 1 valence (NaCl) Halogen 7 valence

55. practice

56. practice
X is a metal, copper is a metal

58. period 3 is row three, metals on left, reactive metal families = 1 & 2, Na in group 1

63. Mass of reactants equals the mass of products
Conservation of Mass
Reactants Products
Mass of reactants equals the mass of products
Number and type of atoms on the reactant side of the equation equals the number and type of atoms on the product side of the equation.
#molecules reactants ≠ #molecules products

64. To check for balance, multiply coefficient x subscript
Are these balanced?
3K + 2B2O3  2K2O + 2B
2Fe + 3Cl2 2FeCl3
KMnO4 +2HCl  KCl + MnCl2 + H2O + Cl2
2C6HCOOH + 13O2  13CO2 + 2H2O
To balance an equation its cool to change coefficients, do not change subscripts….don’t mess w/the little people (you’ll change the molecule’s identity!)
Steps to balance:
Draw a line down the arrow to separate reactants from products
Write down the elements on each side
Multiply coefficients x subscripts to determine numbers of each atom

65. To check for balance, multiply coefficient x subscript
Are these balanced?
3K + 2B2O3  2K2O + 2B unbalanced
2Fe + 3Cl2 2FeCl balanced
KMnO4 +2HCl  KCl + MnCl2 + H2O + Cl2 unbalanced
2C6HCOOH + 13O2  13CO2 + 2H2O unbalanced
To balance an equation its cool to change coefficients, do not change subscripts….don’t mess w/the little people (you’ll change the molecule’s identity!)

66. A reaction has 4 lead atoms in the products, according to the law of conservation of mass, how many lead atoms will be in the reactants? In a reaction, the mass of the reactants is 24g and 8g. Three products are formed, if the mass of two products is 3g and 7g, what is the mass of the third product?

67. A reaction has 4 lead atoms in the products, according to the law of conservation of mass, how many lead atoms will be in the reactants?
4 lead atoms
In a reaction, the mass of the reactants is 24g and 8g. Three products are formed, if the mass of two products is 3g and 7g, what is the mass of the third product? = 32g in reactants
3+7+?=10+?g in reactants
32-10…?=22g third product

75. catalysts are not bonded with reactants or products

78. State of matter (solid, liquid, gas) Melting, freezing, boiling point
Elements and compounds can be described by their chemical and physical properties
Physical property: characteristic of a substance you can observe or measure without changing it into a different substance
State of matter (solid, liquid, gas)
Melting, freezing, boiling point
Magnetism
Density
Color
Shape
Malleability
Solubility
Specific heat

79. Chemical properties: properties of an element or compound in a chemical reactionpH
Reactivity
Flammability

80. Practice on Identifying Chemical and Physical Properties
Water boils at 100 degrees Celsius.
Diamonds are capable of cutting glass.
Water can be separated by electrolysis into hydrogen and oxygen.
Sugar is capable of dissolving in water.
Vinegar will react with baking soda.
Yeast acts on sugar to form carbon dioxide and ethanol.
Wood is flammable.
Aluminum has a low density.
Ammonia is a gas at room temperature.
Bromine has a red color.

81. Practice on Identifying Chemical and Physical Properties
Water boils at 100 degrees Celsius. P
Diamonds are capable of cutting glass. P
Water can be separated by electrolysis into hydrogen and oxygen. C
Sugar is capable of dissolving in water. P
Vinegar will react with baking soda. C
Yeast acts on sugar to form carbon dioxide and ethanol. C
Wood is flammable. C
Aluminum has a low density. P
Ammonia is a gas at room temperature. P
Bromine has a red color. P

82. Changes can be physical or chemical
Physical changes do not rearrange atoms, I have the same substance I started with. I can reverse a physical change Change in shape Change in phase Dissolving These are easily Reversable

83. Chemical change: chemical bonds are broken, atoms are rearranged to form new substances, new chemical bonds are formed
Change in color
Formation of precipitate (L+LS)
Formation of a gas
Change in temperature (exothermic, endothermic)

84. Practice on Identifying Chemical and Physical Changes
You drop the spoon in the disposal and it bends
Koolaid is dissolved in water
Wood in a woodpile begins to decompose
A campfire
The process of respiration takes sugar and oxygen and creates water and carbon dioxide
Making coffee
Lightning converts N2 in the atmosphere to NO3

85. Practice on Identifying Chemical and Physical Changes
You drop the spoon in the disposal and it bends P
Koolaid is dissolved in water P
Wood in a woodpile begins to decompose C
A campfire C
The process of respiration takes sugar and oxygen and creates water and carbon dioxide C
Making coffee P
Lightning converts N2 in the atmosphere to NO3 C

86. Energy in a chemical reaction
Exothermic: releases energy with products
Gets warm or releases light
C6H12O O2  6CO H2O + energy
Endothermic: absorbs energy in reactants
Gets cold
6CO H2O + energy  C6H12O O2

87. More practice Questions

88. C
C & Na Na
6 protons
6 electrons
6 neutrons
2 electron rings
4 valence electrons
Nucleus
Electron cloud
Has p,n,e
11 protons
11 electrons
10 neutrons
3 electron rings
1 valence electron

114. A chemical change produces a new substance, which has different chemical
and physical properties than the reactants that created it.