Valence Electrons

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thanh24mai
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Valence Electrons

Postby thanh24mai » Sun Oct 27, 2019 3:18 pm

How do you count valence electrons?

Mansi_1D
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Joined: Fri Aug 02, 2019 12:15 am

Re: Valence Electrons

Postby Mansi_1D » Sun Oct 27, 2019 3:20 pm

you look at the last digit in the group number for the elements. For example, carbon is in group 14, so it has four valence electrons.

Helen Struble 2F
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Joined: Sat Aug 24, 2019 12:17 am

Re: Valence Electrons

Postby Helen Struble 2F » Sun Oct 27, 2019 3:46 pm

^^It's important to note that this is a shortcut that really only works for the s-block and p-block, when we can assume that most bonding will follow the octet rule. However, there are even exceptions to the octet rule in the p-block—take PCl5. So don't always assume a full octet is a full valence, this isn't always the case!

To find the valence electrons of transition metals (and any element), use the electron configuration. The number of valence electrons will be the total number of electrons in the highest energy shell, across all orbitals. So, if 3 is the highest energy level represented in the electron configuration, the # of valence electrons will be the total electrons in any orbital where n=3. Same goes if the highest energy level represented is n=4, n=5.....the # of valence electrons will be the sum total of electrons with that principle quantum number.

RBergtraun_3A
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Joined: Wed Feb 20, 2019 12:15 am

Re: Valence Electrons

Postby RBergtraun_3A » Sun Oct 27, 2019 4:25 pm

valence electrons are found in the outer most orbital. The number is equal to the atom's main group number. Hopefully that simplifies things.

aishwarya_atmakuri
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Re: Valence Electrons

Postby aishwarya_atmakuri » Sun Oct 27, 2019 4:29 pm

You look at the number of electrons in the outermost shell. This is the number of valence electrons.

katrinawong3d
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Re: Valence Electrons

Postby katrinawong3d » Sun Oct 27, 2019 4:29 pm

valence electrons = the element's group number

Kimme Chun 1I
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Re: Valence Electrons

Postby Kimme Chun 1I » Sun Oct 27, 2019 4:49 pm

For the s and p block, the number of valence electrons is the last number in the group. For the d block, you have to figure out the electron configuration to find how many electrons are in the outermost shell.

Brian J Cheng 1I
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Re: Valence Electrons

Postby Brian J Cheng 1I » Sun Oct 27, 2019 4:52 pm

Valence electrons of a specific element are based on the position the element is inside its period (row). For example, Oxygen is the 6th element in its period (not counting elements in d and f blocks), which means it has 6 valence electrons. Chlorine is the 7th element in its period so it has 7 valence electrons. And all the noble gases are #8 in their periods, which means they have a full valence shell with 8 electrons apiece.

faithkim1L
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Joined: Fri Aug 09, 2019 12:17 am

Re: Valence Electrons

Postby faithkim1L » Sun Oct 27, 2019 5:06 pm

Valence electrons are the number of electrons in the valence (last) shell of the atom. For example, Cl has 7 valence electrons.

Maika Ngoie 1B
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Joined: Fri Aug 02, 2019 12:16 am

Re: Valence Electrons

Postby Maika Ngoie 1B » Sun Oct 27, 2019 5:15 pm

By counting along the period, the number that represents element you are looking for will tell you the valence electrons. For example, Nitrogen is the 5th element in its period, and Florine is the 7th. However, Phosphorous is also has 5 valence electrons, but it is in a different period than Nitrogen.

Matthew Tsai 2H
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Joined: Wed Sep 18, 2019 12:20 am

Re: Valence Electrons

Postby Matthew Tsai 2H » Sun Oct 27, 2019 6:15 pm

For the s and p block elements, the number of valence electrons is just the group number, but it can vary for the d block based on electron configuration. Charged ions may also carry extra or fewer valence electrons.

ABombino_2J
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Re: Valence Electrons

Postby ABombino_2J » Sun Oct 27, 2019 6:37 pm

The valence electrons are electrons in the outer shell. If n=3, all of the electrons in that shell are the valance electrons.

Gabriel Ordonez 2K
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Re: Valence Electrons

Postby Gabriel Ordonez 2K » Sun Oct 27, 2019 6:39 pm

For s and p block elements, start at the metal side and count up from 1 - 8. That's the basic pattern for determining the number of valence electrons. It's slightly different for d-block elements.

305376058
Posts: 35
Joined: Thu Jul 11, 2019 12:17 am

Re: Valence Electrons

Postby 305376058 » Sun Oct 27, 2019 8:53 pm

You can look at the group number to figure this out.

SimranSangha4I
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Joined: Sat Sep 14, 2019 12:17 am

Re: Valence Electrons

Postby SimranSangha4I » Sun Oct 27, 2019 10:05 pm

For the blocks, the amount of valence electrons is based off of the group, or much rather the last shell's electron amount.

Elizabeth Johnson 1I
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Joined: Wed Sep 11, 2019 12:16 am

Re: Valence Electrons

Postby Elizabeth Johnson 1I » Sun Oct 27, 2019 10:52 pm

Kimme Chun 1I wrote:For the s and p block, the number of valence electrons is the last number in the group. For the d block, you have to figure out the electron configuration to find how many electrons are in the outermost shell.

How do you figure out the electron configuration for d block elements?

Shrayes Raman
Posts: 129
Joined: Sat Jul 20, 2019 12:15 am

Re: Valence Electrons

Postby Shrayes Raman » Sun Oct 27, 2019 10:54 pm

For S and P block elements look at the last digit on the group number.


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