1. Atoms, Elements, Compounds

2. Elements
Pure substance that cannot be broken down into other substances
Made of only one kind of atom
More than 100 naturally occurring elements
Periodic table organizes the elements according to their properties

3. Periodic Table
Atomic Number is equal to the number of protons in the nucleus of an atom of the element
A row of elements is called a period
A column of elements is called a group of family

5. Metals
Most elements in the periodic table are metals (left of zig-zag line)
Most metals are solids at room temperature
Are good conductors of heat and electricity
Are shiny (Luster)
Are ductile ( can pulled into wires)
Are malleable (can be bent without breaking)

7. Nonmetals Many are gases at room temperature Are not malleable
Are not ductile
Are not shiny
Are poor conductors of heat and electricity
Located to the right of the zig-zag line

9. Metalloids Have some properties of metals and nonmetal
Are semiconductors
Found along the zig-zag line

11. Atoms
Smallest particle of an element that still has all the properties of an element
Composed of three main types of particles (protons, neutrons, electrons)

13. Protons Positively charged particle Found in the nucleus
Atomic number is equal to the number of protons in an atom

14. Neutrons No charge (are neutral) Also found in the nucleus of an atom
Atomic mass is equal to the number of protons and neutrons in an atom

15. Electrons Negatively charged particle
Move in the space outside of the nucleus
Are arranged in energy levels

16. PEN
P number of protons =
E number of electrons =
N atomic NUMBER

17. Let’s practice! Complete the chart.
Element
Atomic Number
# of Protons
# of Electrons
Sodium 79 32 16
Tin

18. Check your answers ! Element Atomic Number # of Protons # of Electrons
Sodium 11
Gold 79
Germanium 32
Sulfur 16
Tin 50

19. Label the elements in your chart as either metal, nonmetal, or metalloid.

20. Correct Labels Sodium is a metal Gold is a metal
Germanium is a metalloid
Sulfur is nonmetal
Tin is metal (common sense!)

21. More Info…
The atomic mass is equal to the number of protons and neutrons
Unit = amu
Amu = 1/12 the mass of a carbon-12 atom

22. Complete the chart! Atom # of protons # of neutrons Atomic mass 82 207
Krypton 48 31
Xenon

23. Correct Answers Atom # of protons # of neutrons Atomic mass Lead 82
125
207
Krypton 36 48 84
Gallium 31 39 70
Xenon 54 77
131

24. Periods
Are equal to the number of energy levels

25. How many energy levels?
Helium
Sodium
Radium
Cesium

26. Correct answers… Helium = 1 energy levels Sodium = 3 energy levels
Radium = 7 energy levels
Cesium = 6 energy levels

27. Families and groups Similar structure Similar properties
May correspond to the number of electrons in the last energy level (outer ring or shell)

28. Examples Sodium = 1 electron Potassium = 1 electron
Oxygen = 6 electrons
Tellurium = 6 electrons
Xenon = 8 electrons

29. 8 is the lucky number!
Atoms are more stable if they have 8 electrons in their highest energy level.
May combine together to make the number 8! (Becomes a compound!)

30. Example Sodium = 1 Chlorine = 7
Combine (1 + 7 = 8) Sodium Chloride or table salt

31. Compounds Forms when two or more different atoms combine
Have properties that are different from those of the atoms from which they are made

32. Example Hydrogen is an explosive gas
Oxygen is a gas that is needed to support a flame
When chemically combined they form water which is used to put out most fires!

33. Molecular Compounds
Form when different atoms share their outermost electrons
Example – two atoms of hydrogen can share one electron with oxygen

34. Ions Forms when an atom or group of atoms gain or lose an electron
Positive ion – loses electrons
Negative ion – gains electrons

35. Ionic Compound
Ions of opposite electric charges attract one another to form electrically neutral compounds
Example - NaCl

36. Organic Compounds Always contain carbon and hydrogen
Product of living things
Examples – Carbohydrates, Lipids, Proteins, & Nucleic Acids

37. Inorganic Compounds Are made of elements other than carbon
Examples of important inorganic compounds are water, calcium phosphate, hydrochloric acid, sodium bicarbonate, sodium chloride

38. Finding the number of atoms in a formula
Example 1: C12H22O11
Write down the formula
Place an arrow over each capital letter
Write the symbol
Write the name of the element
Write the number of atoms for each element
Add up the total amount of atoms

39. C12H22O11 C Carbon – 12 H Hydrogen – 22 O Oxygen – 11
Total =
Total = 45 atoms

40. Example 2 Ca(NO3)2 Ca Calcium – 1 N Nitrogen – 2 Oxygen – 6
Total =
Total = 9 atoms

41. Now you try!
Pb(NO3)2

42. Pb(NO3)2
Pb Lead – 1
N Nitrogen – 2
O Oxygen – 6
Total =
Total = 9 atoms

43. Example 3: Coefficients! 4Al2(SO4)3
The large number 4 means 4 molecules of Aluminum Sulfate or 4 times everything!

44. 4Al2(SO4)3 Al Aluminum – 8 S Sulfur – 12 O Oxygen – 48
Total = 68 atoms!

45. You try!
2Mg(C7H5O3)2

46. Solution 2Mg(C7H5O3)2 Mg Magnesium = 2 C Carbon = 28 H Hydrogen = 20
O Oxygen = 12
Total = 62

47. Now, balancing chemical equations!

48. Is it balanced? If not, balance the following!

49. HCl + KOH  KCl + H2O

50. It is balanced!!!!!!

51. Al + S8  Al2S8

52. Answer
2Al + S8  Al2S8

53. H3PO4 + Ca(OH)2  Ca3(PO4)2 + H20

54. 2H3PO4 + 3Ca(OH)2  Ca3(PO4)2 + 6H2O

55. K + O2  K2O

56. Answer
4K + O2  2K2O