11. The Periodic Table
G R O U P S
P E R I O D S

20. The Periodic Table
HALOGENS

22. The Periodic Table
The Noble Gases

30. Representing Atoms
The Atomic Number is also the number of PROTONS (or electrons)
The Atomic Symbol Na 11
The Atomic Mass in amu’s
22.99

33. C C Of Isotopes and Atoms! 6 6 12.00 14.00 SAME # of Protons
Isotopes have different masses from one another.
The different mass is a result of different numbers of neutrons.

45. THE ORDER OF FILLING
4th p s d
3rd p s p
2nd s
1st s e H
1 proton

46. f d
4th p s d
3rd p s p
2nd s
1st s
e e He
2 protons

47. f d
4th p s d
3rd p s p
2nd s e
1st s
e e Li
3 protons

48. f d
4th p s d
3rd p s p
2nd s
e e
1st s
e e Be
4 protons

49. f d
4th p s d
3rd p s e p
2nd s
e e
1st s
e e B
5 protons

50. f d
4th p s d
3rd p s e e p
2nd s
e e
1st s
e e C
6 protons

51. f d
4th p s d
3rd p s e e e p
2nd s
e e
1st s
e e N
7 protons

52. f d
4th p s d
3rd p s
e e
e e
e e p
2nd s
e e
1st s
e e Ne
10 protons

53. Na 4th 3rd 2nd 1st 11 protons e e e e e e e e e e e f d p s d p s p s

54. Mg 4th 3rd 2nd 1st 12 protons e e e e e e e e e e e e f d p s d p s p