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Periodic Table www.middleschoolscience.comwww.middleschoolscience.com 2008 How to Draw Bohr Diagrams.

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Presentation on theme: "Periodic Table www.middleschoolscience.comwww.middleschoolscience.com 2008 How to Draw Bohr Diagrams."— Presentation transcript:

1 Periodic Table www.middleschoolscience.comwww.middleschoolscience.com 2008 How to Draw Bohr Diagrams

2 Learning Scale 4 – Investigate and describe the compounds formed by bonding elements. 3 – Describe why certain elements bond with others. 2 – Use the periodic table to identify the number of protons, neutrons, or electrons in an element. 1 – Identify patterns on the periodic table.

3 Review – Timed Pair Share You have 30 seconds to share with your partner. 1.How can you determine the number of protons, electrons, and neutrons in an element?

4 Review – Timed Pair Share 1.Explain how the periodic table is organized and how it is useful to scientists.

5 Previewing Content Why is it important for elements to be able to join together to form compounds?

6 Energy Levels How many electrons can each level hold? 1 st level = 2 2 nd level = 8 3 rd level = 18 4 th level = 32

7 Valence Electrons Valence electrons are the electrons found in the outer energy level. We will only be using Groups 1-2 and Groups 13-18.

8 Valence Electrons The last number of the group number = the number of valence electrons. Examples Group 2 = 2 valence electrons Group 18 = 8 valence electrons

9 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.

10 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. www.chem4kids.com

11 Bohr Diagrams C C 1) Draw a nucleus with the element symbol inside. 2) Carbon is in the 2 nd period, so it has two energy levels, or shells. 3) Draw the shells around the nucleus.

12 Bohr Diagrams 1) Add the electrons. 2) Carbon has 6 electrons. 3) The first shell can only hold 2 electrons. C C

13 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. C C

14 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. C C

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

16 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

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

18 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

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

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

21 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

22 Which elements want to bond? Octet Rule The magic number for all elements (except H and He) is 8. This means that they will gain or lose electrons in order to get 8 in their outer energy level.

23 Who gains? Who loses? More electrons = gain Less electrons = lose

24 Review Questions  Group 1 has __ valence electrons. It needs _.  Which group will it bond with? Why?  Will it lose or gain electrons?  Group 16 has __ valence electrons. It needs _.  Which group will it bond with? Why?  Will it lose or gain electrons?

25 Learning Scale 4 – Investigate and describe the compounds formed by bonding elements. 3 – Describe why certain elements bond with others. 2 – Use the periodic table to identify the number of protons, neutrons, or electrons in an element. 1 – Identify patterns on the periodic table.


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