1. Using the Main Group Elements of the Periodic Table to Draw Bohr-Rutherford Diagrams
1.01 1 He
4.00 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Li Be B C N O F Ne Na Mg K Ca Al Si P S Cl Ar
6.94
9.01
10.81
12.01
14.01
16.00
19.00
20.18
22.99
24.31
26.98
28.09
30.97
32.07
35.45
39.95
39.10
40.08 2A 3A 4A 5A 6A 7A 8A

2. K Nuclear Notation The Atomic Number
Indicates the number of protons in an atom
Protons give the location and identity of the element on the periodic table. 19 K
39.1
atomic number

3. Rules of Atomic Structure
Atomic number = number of protons
2. Mass number = number of protons + number of neutrons
How do we determine the number of neutrons in an element?
3. Number of neutrons = mass number (rounded to the nearest whole number) – atomic number
3. Number of protons = number of electrons in a neutral atom

4. K K Nuclear Notation The Mass Number The rounded atomic mass
Indicates the number of protons & neutrons in the nucleus of the atom 19 K
39.1
atomic mass
Nuclear Notation 39 K 19
rounded 39

5. The Bohr-Rutherford Model
Graphic Representation of the Main Group Elements from #’s 1-20
Main group elements are elements in families 1A, 2A, 3A, 4A, 5A, 6A, 7A & 8A
The Radius of electron cloud is approximately times larger than the nucleus
This model atom is similar to our Solar System  electrons are found in distinct orbits around the nucleus
Orbits for electrons are referred to as orbital shells and are drawn as circles around the nucleus.

6. Orbital Shells p + n nucleus (protons + neutrons)
1st shell (max. 2 electrons)
2nd shell (max. 8 electrons)
3rd shell (max. 8 electrons)
4th shell (max. 2 electrons)

7. Valence Electrons
Valence electron: Electron in the outer shell of an atom that can participate in forming chemical bonds with other atoms

8. Valence Electrons
Family 1A elements  1 valence electron Family 2A elements  2 valence electrons Family 3A elements  3 valence electrons Family 4A elements  4 valence electrons Family 5A elements  5 valence electrons Family 6A elements  6 valence electrons Family 7A elements  7 valence electrons Family 8A elements  8 valence electrons

9. 1A 8A H
1.01 1 2 He 2A 3A 4A 5A 6A 7A
4.00 3 4 5 6 7 8 9 10 Li Be B C N O F Ne
6.94
9.01
10.81
12.01
14.01
16.00
19.00
20.18 11 12 13 14 15 16 17 18 Na Mg Al Si P S Cl Ar
22.99
24.31
26.98
28.09
30.97
32.07
35.45
39.95 19 20 K Ca
39.10
40.08

10. Bohr-Rutherford diagram
HYDROGEN (H)
Bohr-Rutherford diagram
PROTONS: 1 NEUTRONS: 0
Nuclear Notation
P-1 N-0 1 H 1

11. Bohr-Rutherford diagram
HELIUM (He)
PROTONS: 2 NEUTRONS: 2
Bohr-Rutherford diagram
Nuclear Notation
P-2 N-2 4 He 2

12. Bohr-Rutherford diagram
LITHIUM (Li)
PROTONS: 3 NEUTRONS: 4
Bohr-Rutherford diagram
Nuclear Notation
P- 3 N-4 7 Li 3

13. Bohr-Rutherford diagram
BERYLLIUM (Be)
PROTONS: 4 NEUTRONS: 5
Bohr-Rutherford diagram
Nuclear Notation
P- 4 N-5 9 Be 4

14. Bohr-Rutherford diagram
BORON (B)
PROTONS: 5 NEUTRONS: 6
Bohr-Rutherford diagram
Nuclear Notation
P- 5 N-6 11 B 5

15. Bohr-Rutherford diagram
CARBON (C)
PROTONS: 6 NEUTRONS: 6
Bohr-Rutherford diagram
Nuclear Notation
P- 6 N-6 12 C 6

16. Bohr-Rutherford diagram
NITROGEN (N)
PROTONS: 7 NEUTRONS: 7
Bohr-Rutherford diagram
Nuclear Notation
P- 7 N-7 14 N 7

17. Bohr-Rutherford diagram
OXYGEN (O)
PROTONS: 8 NEUTRONS: 8
Bohr-Rutherford diagram
Nuclear Notation
P- 8 N-8 16 O 8

18. Bohr-Rutherford diagram
FLUORINE (F)
PROTONS: 9 NEUTRONS: 10
Bohr-Rutherford diagram
Nuclear Notation
P- 9 N-10 19 F 9

19. Bohr-Rutherford diagram
NEON (Ne)
PROTONS: 10 NEUTRONS: 10
Bohr-Rutherford diagram
Nuclear Notation
P- 10 N-10 20 Ne 10

20. Bohr-Rutherford diagram
SODIUM (Na)
PROTONS: 11 NEUTRONS: 12
Bohr-Rutherford diagram
Nuclear Notation
P- 11 N-12 23 Na 11

21. Bohr-Rutherford diagram
MAGNESIUM (Mg)
PROTONS: 12 NEUTRONS: 12
Bohr-Rutherford diagram
Nuclear Notation
P- 12 N-12 24 Mg 12

22. Bohr-Rutherford diagram
ALUMINUM (Al)
PROTONS: 13 NEUTRONS: 14
Bohr-Rutherford diagram
Nuclear Notation
P- 13 N-14 27 Al 13

23. Bohr-Rutherford diagram
SILICON (Si)
PROTONS: 14 NEUTRONS: 14
Bohr-Rutherford diagram
Nuclear Notation
P- 14 N-14 28 Si 14

24. Bohr-Rutherford diagram
PHOSPHORUS (P)
PROTONS: 15 NEUTRONS: 16
Bohr-Rutherford diagram
Nuclear Notation
P- 15 N-16 31 P 15

25. Bohr-Rutherford diagram
SULFUR (S)
PROTONS: 16 NEUTRONS: 16
Bohr-Rutherford diagram
Nuclear Notation
P- 16 N-16 32 S 16

26. Bohr-Rutherford diagram
CHLORINE (Cl)
PROTONS: 17 NEUTRONS: 18
Bohr-Rutherford diagram
Nuclear Notation
P- 17 N-18 35 Cl 17

27. Bohr-Rutherford diagram
ARGON (Ar)
PROTONS: 18 NEUTRONS: 22
Bohr-Rutherford diagram
Nuclear Notation
P- 18 N- 22 40 Ar 18

28. Bohr-Rutherford diagram
POTASSIUM (K)
Bohr-Rutherford diagram
PROTONS: 19 NEUTRONS: 20
Nuclear Notation
P- 19 N-20 39 K 19

29. Bohr-Rutherford diagram
CALCIUM (Ca)
Bohr-Rutherford diagram
PROTONS: 20 NEUTRONS: 20
Nuclear Notation
P- 20 N-20 40 Ca 20