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### VALENCE ELECTRONS

Posted: Sun May 13, 2018 10:09 pm
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?

### Re: VALENCE ELECTRONS

Posted: Sun May 13, 2018 10:12 pm
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.

### Re: VALENCE ELECTRONS

Posted: Sun May 13, 2018 10:13 pm
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.

### Re: VALENCE ELECTRONS

Posted: Sun May 13, 2018 10:15 pm
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.

### Re: VALENCE ELECTRONS

Posted: Sun May 13, 2018 10:22 pm
How do valence electrons influence Lewis structures? Are they represented in any particular way?

### Re: VALENCE ELECTRONS

Posted: Sun May 13, 2018 10:27 pm
The electrons you draw in Lewis structures are valence electrons.

### Re: VALENCE ELECTRONS

Posted: Sun May 13, 2018 10:33 pm
Yes, you have to use the number of valence electrons in order to conduct your Lewis dot diagrams.

### Re: VALENCE ELECTRONS

Posted: Sun May 13, 2018 11:16 pm
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.

### Re: VALENCE ELECTRONS

Posted: Sun May 13, 2018 11:19 pm
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?

### Re: VALENCE ELECTRONS

Posted: Mon May 14, 2018 1:00 am
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!

### Re: VALENCE ELECTRONS

Posted: Mon May 14, 2018 1:02 am
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!

### Re: VALENCE ELECTRONS

Posted: Mon May 14, 2018 1:34 am
The number of valence electrons for each group.

### Re: VALENCE ELECTRONS

Posted: Mon May 14, 2018 1:59 am
I find it easy to just look at the group that the element is in. This video provides a helpful explanation

### Re: VALENCE ELECTRONS

Posted: Mon May 14, 2018 2:05 am
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.

### Re: VALENCE ELECTRONS

Posted: Mon May 14, 2018 11:15 am
I like to use the group numbers and subtract 10 as we approach the non-metals.

### Re: VALENCE ELECTRONS

Posted: Mon May 14, 2018 12:15 pm
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.

### Re: VALENCE ELECTRONS  [ENDORSED]

Posted: Mon May 14, 2018 3:27 pm
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.