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Valence Electrons

Posted: Sun Oct 27, 2019 3:18 pm
How do you count valence electrons?

Re: Valence Electrons

Posted: 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.

Re: Valence Electrons

Posted: 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-blockâ€”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.

Re: Valence Electrons

Posted: 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.

Re: Valence Electrons

Posted: 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.

Re: Valence Electrons

Posted: Sun Oct 27, 2019 4:29 pm
valence electrons = the element's group number

Re: Valence Electrons

Posted: 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.

Re: Valence Electrons

Posted: 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.

Re: Valence Electrons

Posted: 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.

Re: Valence Electrons

Posted: 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.

Re: Valence Electrons

Posted: 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.

Re: Valence Electrons

Posted: 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.

Re: Valence Electrons

Posted: 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.

Re: Valence Electrons

Posted: Sun Oct 27, 2019 8:53 pm
You can look at the group number to figure this out.

Re: Valence Electrons

Posted: 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.

Re: Valence Electrons

Posted: 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?

Re: Valence Electrons

Posted: Sun Oct 27, 2019 10:54 pm
For S and P block elements look at the last digit on the group number.