Valence Electrons [ENDORSED]

[Inderpal Singh 2L]

How does the professor calculate the number of valence electrons in an element so quickly? Does it have something to do with its position in a column of the periodic table? (Oxygen has 6 VE)

[Sydney Lam_2I]

Hi,

The professor has probably done this a lot so he's memorized the number of valence electrons for common elements. Also, yes you can know how many valence electrons you have through the periodic table by counting the s and p orbitals.

[George_Yin_3I]

Regarding the number of valence number, you just have to consider the outer most shell of the atom and subtract all electrons from inner shells.

[George_Yin_3I]

Regarding the number of valence number, you just have to consider the outer most shell of the atom and subtract all electrons from inner shells.

[Jasmine Ho 3I]

The number of valence electrons corresponds to that element's column in the periodic table, ignoring the entire d-block. So, any element in the 1st column has 1 valence electron; any element in the "5th" column (the column with N at the top) has 5 valence electrons, etc.

[Anya Holbrook 1E]

Yes, you're right! The column number that the element is in, is the number of valence electrons that the element has. Keep in mind that wwhen I say column number, it only applies to the s and p blocks, not the d block.

[MCalcagnie_ 1D]

If the d-block doesn't follow this pattern, how do we determine the number of valence electrons in the d or f block?

[Daniela Santana 2L]

Hi! Yes you can find the amount of valence electrons for each element by looking at the periodic table. For example, in the image of the periodic table I attached the underlined value is the number of valence electrons for that specific element. Its usually the last number after the last hyphen. Hope this helps!

[Keon Amirazodi 3H]

You can identify the number of valence electrons quickly based on the group that the element is in. Atoms in the 1st group have 1 valence electrons while atoms in the 8th group (noble gases) have 8. Exclude the d block when counting the group.

[chinmayeec 2H]

The number of valence electrons is based on the number of electrons in the outermost shell of the atom (which is also the highest principle quantum number of shells in the atom). So for example, oxygen goes up to n=2 and it has 6 electrons in the n=2 shell (2 electrons in the 2s subshell and 4 electrons in the 2p subshell). To find it the number of valence electrons quickly, it would be easiest to use the group number.

Hope that helps!

[Brian_Wu_3B]

Cutting out the d block, the first group (column) has 1 VE and the second group has 2VE, then hopping over to the p-block, the column with Boron has 3VE and so on until the noble gases which have 8.

[jasmineculilap_3F]

You can find VE quickly by counting which group it's in. There are 8 groups from left to right when you don't include the d-block/transition metals, and the group it's in corresponds to the element's valence electrons.

[Sameer Chowdhury 3C]

From my understanding all the families have the same amount of valence electrons, so in order to know say how many valence electrons bromine has, all you would need to know is how many valence electrons fluorine has (1). Also I think it's just because Lavelle so much practice doing chemistry.

[Griffin G]

The number of valence electrons does have to do with which group, generally. This is true for elements that aren't in the middle chunk of the periodic table.

[Gian Boco 2G]

Based on the group that the element falls under on the periodic table, you can determine the number of valance electrons. On the S block, Group 1 (alkali metals) have 1 valence electron and Group 2 (alkali earth metals) have 2 valence electrons. Skipping all the way to the p block, the Boron group has 3, then the carbon group has 4, then the nitrogen group has 5, then the oxygen group has 6, and the halogens (the group under fluorine) has 7.

[joshtully]

You can figure out the valence electrons of an element by counting which column it is in, skipping the d block.

[Ayesha Aslam-Mir 3C]

Is there a way to use the electron configurations to know the valence electrons in transition metals?

[abby hyman]

The number of valence electrons is found by going across the period of the element and counting how many. So carbon would be 4, oxygen 6 etc.

[Ashlen Bullock 1H]

To calculate the number of valence electrons, subtract the total number of electrons (equal to the atomic number) by the number of shielding electrons.

[Mehreen 3I]

The columns of the periodic table will help you calculate the number of valence electrons, and this only applies for the s and p orbitals not the d block.

[LaurenChoi_1J]

Yes! There's also a bunch of images online that have periodic tables labeled with the valence electrons that can be really helpful to add to your notes!

[Heidi Buri 2I]

Hi! Yes the placement of elements on the periodic table can provide insight on the number of valence electrons. Specifically, elements within the 1-2 and 13-18 columns, the number of valence electrons increased (1 valence electron for hydrogen and 8 valence electrons for He).

[Katie Nye 2F]

You can either calculate the number of valence electrons based on the number of electrons and then subtracting the inner ones or looking at the periodic table. Personally, I prefer the periodic table because it is faster and easier. You just look at what group the element is in and that is the number of valence electrons.

[Katie Le 3K]

Yea the group number corresponds with the number of valence electrons.

[Kendall_Dewey_2D]

The number of valence electrons can be quickly found depending on which group that the element is in on the periodic table. So, atoms in the 1st group have 1 valence electron, while atoms in the 8th group (noble gases) have 8, and don't forget to exclude the d block when you count the group!

[505598869]

An easy way to find the number of valence electrons is by using the group that an atom is in. Group one atoms have 1 valence electron and those in group 8 (noble gases) have 8 valence. Do not count the d block while counting the groups.

[Will Skinner]

To find the number of valence electrons, I look at the number of the column. For the elements of the s and p blocks, the digit in the one’s place is the # of valence e-. For example, O is in the 16th column and has 6 valence e-. F is in the 17th column and has 7 valence e-.

[Sreeram Kurada 3H]

Yeah, each column is +1 valence electron, that is until you go to the column that has carbon. Then after carbon, the columns after that go from -3 to 0 formal charge.

[Juliana Rosales 1H]

He probably knows from doing them so much and for so long. I can tell by looking at the column that they are it. On the top of the periodic columns there are numbers that will label the column.

[105618850]

Hey! It's pretty simple actually, well only when it concerns the s and p blocks. The number of valence electrons are separated into into the different columns of the periodic table. you can search it up online and it will offer a little trick to memorizing the amount of valence electrons using the periodic table. Note that the trick doesn't apply to anything above the p block.

[Nan_Guan_1L]

excluding the d block, you can just look what column is the element in. elements in the first column has 1 valence electron and etc. for the d block, you can write out its electron configuration and see how many valence electrons it have.

[Yolanda_Xing_3A]

Hi! The professor are probably used to calculate these. I think a great way to speed up the calculation is to 1) simplify your steps and 2) decrease chances of mistake.

Only count the outer election: simply count the boxes on the period table from the left within the same period( skip the d block). Then count the elections you used while placing to the Lewis structure. Through more practices, you will be more experienced.

[Katelyn_Ortega_1D]

The number of valence electrons an element has is labeled on the periodic table. With the exception of the d-block, the elements have the amount of valence electrons they have labeled on top of each column.

[Carly_Lipschitz_3H]

Dr. Lavelle calculates the number of valence electrons in an element so quickly by using the periodic table. You're right that the column on the periodic table determines the number of valence electrons. For elements in the s- and p-blocks, you just count up starting from 1 valence electron in the first column to a complete octet in the noble gas column on the far right of the table. All of the elements in the same group/column have the same number of valence electrons.

[Madeline Ogden 3B]

For elements not in the d-block the amount of valence electrons can be found by looking at the periodic table. Group 1 (hydrogen, lithium, etc.) has one, group 2 (beryllium, magnesium, etc.) has two and so on up until the 8th group where the noble gases are. To find valence electrons in the d- or f-block elements, simply find their electron configuration using the Aufbau principle. The shell that's unfilled is the one holding the atom's valence electrons. Hope this helps!

[Charlotte Adams 1A]

You can use the group number to determine the number of valence electrons or you can figure out the electron configuration but that takes a while.

[Sydney Jensen 3L]

The columns on the periodic table correlate with the number of valence electrons when considering the s and p groups.

[abby hyman]

For the s and p orbitals, you can use the group number to tell you how many valence electrons an element has, and for the d block, you can think about writing the halogen electron configuration and see how many electrons are written

[George_Yin_3I]

Valence electrons are basically electrons on the outer shell, which you can easily calculate by subtracting all electrons in inner shells.

[805593945]

just use the group to determine the ve-

[Caelin Brenninkmeijer 1G]

You can use the group number to determine how many valence electrons are present in an element. For example, elements in group 1 have one valence electron while elements in group 6 have six. In regards to elements in the d-block, you could use electron configurations to derive the number of valence electrons.

[Aria Movassaghi 1A]

its the number of electrons in thee outer shell but you can also just memorize by the column the element is in

[Brandon Carris]

I'm pretty sure he memorized all the values cause he's been in the game for a while.

[Chem_Mod]

I'm pretty sure he memorized all the values cause he's been in the game for a while.

But when I get tired I look at the periodic table and count the columns. :-)

[Nishan Reddy 3K]

Each group in the periodic table is organized in such a way that the number of valence electrons increases going from left to right across the periodic table. Each group share the same number of valence electrons unless they are within the transition metal portion of the periodic table.

[Emily Wu 2G]

Hi, the way I do it is that I look at where it is on the periodic table, count from the left to right and whatever place is it should be the number of valence electrons in there.

[Mahima Manoj 1F]

I usually look at the group number for the s and p block to figure out the valence electrons. For example, N is group 5 and has 5 valence electrons