## VALENCE ELECTRONS [ENDORSED]

april_bussey_1C
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### VALENCE ELECTRONS

Hi all, I'm still having a hard time understanding how to know how many valence electrons a specific element has. Can anyone help me out?

404975170
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### Re: VALENCE ELECTRONS

You just look at the periodic table and count what position the element is in in the row (excluding d block). For example: Oxygen has 6 valence electrons and Flourine has 7 and Carbon has 4 valence electrons.

Isobel Tweedt 1E
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Joined: Fri Apr 06, 2018 11:05 am

### Re: VALENCE ELECTRONS

Look at the group of the periodic table that the element is in. For example, Carbon is in group 4 and has 4 valence electrons.

Tiffany Tufenkjian 1E
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Joined: Fri Apr 06, 2018 11:05 am

### Re: VALENCE ELECTRONS

I count the columns of the s and p block. For example, in row 2 Li=1 valence electron, BE=2, B=3, C=4, N=5, O=6, F=7, Ne=8.

Isobel Tweedt 1E
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### Re: VALENCE ELECTRONS

How do valence electrons influence Lewis structures? Are they represented in any particular way?

Chem_Mod
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### Re: VALENCE ELECTRONS

The electrons you draw in Lewis structures are valence electrons.

fara valdez
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### Re: VALENCE ELECTRONS

Yes, you have to use the number of valence electrons in order to conduct your Lewis dot diagrams.

Jennifer 1G
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### Re: VALENCE ELECTRONS

You can tell how many valence electrons there are by checking on the vertical line the element is on. For example, Hydrogen has 1 valence electron and Oxygen has 6.

Rebekah Kaufman 1L
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### Re: VALENCE ELECTRONS

Miranda Hughes 1F wrote:You just look at the periodic table and count what position the element is in in the row (excluding d block). For example: Oxygen has 6 valence electrons and Flourine has 7 and Carbon has 4 valence electrons.

Why is the d block excluded when counting valence electrons?

Jennifer 1G
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Joined: Wed Nov 15, 2017 3:03 am

### Re: VALENCE ELECTRONS

Jennifer 1G wrote:You can tell how many valence electrons there are by checking on the vertical line the element is on. For example, Hydrogen has 1 valence electron and Oxygen has 6.

As part of my previous post- According to google, Helium has two valence electrons, so this pattern may not always work. Why is helium located there and are there any other exceptions? Thank you!

Jennifer 1G
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Joined: Wed Nov 15, 2017 3:03 am

### Re: VALENCE ELECTRONS

Jennifer 1G wrote:
Jennifer 1G wrote:You can tell how many valence electrons there are by checking on the vertical line the element is on. For example, Hydrogen has 1 valence electron and Oxygen has 6.

As part of my previous post, according to google, Helium has two valence electrons, so this pattern may not always work. Why is helium located there and are there any other exceptions? Thank you!

Nandhini_2K
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Joined: Fri Apr 06, 2018 11:03 am

### Re: VALENCE ELECTRONS

The number of valence electrons for each group.
Attachments

Ziana Bhanji 1E
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### Re: VALENCE ELECTRONS

I find it easy to just look at the group that the element is in. This video provides a helpful explanation

breannasung_1K
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Joined: Fri Apr 06, 2018 11:05 am

### Re: VALENCE ELECTRONS

knowing that the first shell is occupied by 2 electrons, i subtract 2 from the atomic number, which tells how many electrons an atom has. All the elements in a column have the same number of valence electrons.

nelquosey
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Joined: Fri Apr 06, 2018 11:02 am

### Re: VALENCE ELECTRONS

I like to use the group numbers and subtract 10 as we approach the non-metals.

Haison Nguyen 1I
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Joined: Fri Apr 06, 2018 11:04 am

### Re: VALENCE ELECTRONS

You look at the group numbers or the rows of each element. However, I skip the d-block so where Boron is at would be group 3. For hydrogen, since it is in group 1, it has one valence electron. For another element like carbon, since it is group 4, it would have 4 valence electrons.

Chem_Mod
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### Re: VALENCE ELECTRONS  [ENDORSED]

Just look at the "pillars" of the periodic table (meaning exclude the d block). The column they are in indicates the number of valence electrons. Helium is a special exception (and the only one). It only has 2 valence electrons, and this is because A) it only has two electrons to begin with, and B) it's extremely stable because its outermost shell is full. 1s2 is it's electron configuration, which you will understand better later in the course.