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Bohr Model Lewis Structure. Bohr Model Introduced in 1913 by Niels Bohr Depicts the atom as a small, positively charged nucleus surrounded by electrons.

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Presentation on theme: "Bohr Model Lewis Structure. Bohr Model Introduced in 1913 by Niels Bohr Depicts the atom as a small, positively charged nucleus surrounded by electrons."— Presentation transcript:

1 Bohr Model Lewis Structure

2 Bohr Model Introduced in 1913 by Niels Bohr Depicts the atom as a small, positively charged nucleus surrounded by electrons. Why do we use the Bohr model? – Simple and easy to understand – Representation of subatomic particles – Valence Electrons

3 How to Draw Bohr Diagrams

4 Bohr Diagrams 1)Find your element on the periodic table. 2)Determine the number of electrons – it is the same as the atomic number. 3)This is how many electrons you will draw.

5 Bohr Diagrams Find out which period (row) your element is in. Elements in the 1 st period have one energy level. Elements in the 2 nd period have two energy levels, and so on.

6 Bohr Diagram Energy Level Electron Capacity ges/81/different-energy-levels.png

7 Bohr Diagrams P - 6 N- 6 P - 6 N- 6 1) Draw a nucleus with the p and n in the nucleus. 2) Carbon is in the 2 nd period, so it has two energy levels, or shells. 3) Draw the shells around the nucleus. 4) Put how many protons and neutrons in the center

8 Bohr Diagrams 1) Add the electrons. 2) Carbon has 6 electrons. 3) The first shell can only hold 2 electrons. P- 6 N - 6 P- 6 N - 6

9 Bohr Diagrams 1) Since you have 2 electrons already drawn, you need to add 4 more. 2) These go in the 2 nd shell. 3) Add one at a time - starting on the right side and going counter clock-wise. PNPN PNPN

10 Bohr Diagrams 1) Check your work. 2) You should have 6 total electrons for Carbon. 3) Only two electrons can fit in the 1 st shell. 4) The 2 nd shell can hold up to 8 electrons. 5) The 3 rd shell can hold 18, but the elements in the first few periods only use 8 electrons. PNPN PNPN

11 Bohr Diagrams Try the following elements on your own: a)H b)He c)O d)Al e)Ne f)K PNPN PNPN

12 Bohr Diagrams Try the following elements on your own: a)H – 1 electron b)He c)O d)Al e)Ne f)K H H

13 Bohr Diagrams Try the following elements on your own: a)H b)He - 2 electrons c)O d)Al e)Ne f)K He

14 Bohr Diagrams Try the following elements on your own: a)H b)He c)O - 8 electrons d)Al e)Ne f)K O O

15 Bohr Diagrams Try the following elements on your own: a)H b)He c)O d)Al - 13 electrons e)Ne f)K Al

16 Bohr Diagrams Try the following elements on your own: a)H b)He c)O d)Al e)Ne - 10 electrons f)K Ne

17 Bohr Diagrams Try the following elements on your own: a)H b)He c)O d)Al e)Ne f)K - 19 electrons K K

18 Lewis Structure Electron-dot diagrams Represents paired and unpaired valence electrons in an atom Covalent Bond- sharing electrons Valence Electron- electrons in the outer most shell; electrons that are transferred or shared when atoms bond together

19 How to Draw Lewis Structures

20 Lewis Structures 1)Find your element on the periodic table. 2)Determine the number of valence electrons. 3)This is how many electrons you will draw.

21 Lewis Structures Find out which group (column) your element is in. This will tell you the number of valence electrons your element has. You will only draw the valence electrons.

22 Groups - Review Each column is called a “group” Each element in a group has the same number of electrons in their outer orbital, also known as “shells”. Except for He, it has 2 electrons The electrons in the outer shell are called “valence electrons”

23 Lewis Structures 1) Write the element symbol. 2) Carbon is in the 4 th group, so it has 4 valence electrons. 3) Starting at the right, draw 4 electrons, or dots, counter- clockwise around the element symbol.

24 Lewis Structures 1) Check your work. 2) Using your periodic table, check that Carbon is in the 4 th group. 3) You should have 4 total electrons, or dots, drawn in for Carbon.

25 Lewis Structures On your worksheet, try these elements on your own: a)H b)P c)Ca d)Ar e)Cl f)Al

26 Lewis Structures On your worksheet, try these elements on your own: a)H b)P c)Ca d)Ar e)Cl f)Al

27 Lewis Structures On your worksheet, try these elements on your own: a)H b)P c)Ca d)Ar e)Cl f)Al

28 Lewis Structures On your worksheet, try these elements on your own: a)H b)P c)Ca d)Ar e)Cl f)Al

29 Lewis Structures On your worksheet, try these elements on your own: a)H b)P c)Ca d)Ar e)Cl f)Al

30 Lewis Structures On your worksheet, try these elements on your own: a)H b)P c)Ca d)Ar e)Cl f)Al

31 Lewis Structures On your worksheet, try these elements on your own: a)H b)P c)Ca d)Ar e)Cl f)Al

32 Complete the Lewis Structure Worksheet You should know how to draw Lewis Structures for the first 20 elements.

33

34 1. The Bohr Model was introduced by which of the following scientists A.Albert Einstein B.Neils Bohr C.Charles Darwin D.Gregor Mendel

35 2. The Bohr model depicts A.The atom as a small positively charged nucleus surrounded by electrons. B.Paired and unpaired valence electrons in an atom. C.Covalent bonds D.Valence Electrons

36 3. In the periodic table, the rows represent A.Groups B.Covalent Bonds C.Ionic Bonds D.Periods

37 4. In the periodic table, the columns represent A.Periods B.Covalent Bonds C.Groups D.Ionic Bonds

38 5. The Lewis Structure represents A.Paired and unpaired valence electrons in an atom. B.The atom as a small positively charged nucleus surrounded by electrons. C.Valence Electrons

39 6. When drawing a Bohr model, how do you determine the number of electrons? A.Valence Electrons B.Mass Number C.Atomic Number D.Atomic Mass Unit

40 7. When drawing a Lewis Structure, how do you determine the number of valence electrons? A.Atomic Number B.Mass Number C.Atomic Mass Unit D.By looking at the column the element is found in

41 8. The Lewis Structure is also known as A.Bohr Model B.The electron dot diagram C.Valence Electrons D.The planetary model

42 9. When drawing a Lewis Structure, in which direction do you move when drawing the dots? A.Counter-clockwise around the element B.Clockwise around the element C.North D.Southwest

43 10. When drawing a Bohr model, how do you determine the number of energy levels to use? A.Groups B.Columns C.Periods D.Atomic Number [Default] [MC Any] [MC All]


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