Aufbau Principle (Periodic Table Labels).mp4
Summary
TLDRThis vodcast explains how to label the periodic table to understand electron configurations, focusing on the Aufbau principle. It highlights how electrons fill lower energy orbitals first and introduces labeling sections for s, p, d, and f blocks. The video also covers orbital overlap, particularly the 3d and 4s energy levels, and guides viewers through the proper order for filling orbitals across the periodic table. Finally, it reassures viewers that they don't need to stress over the f-block elements due to their limited role in most chemistry studies.
Takeaways
- 📝 The video explains how to label the periodic table with electron configurations using the Aufbau principle.
- 🔋 The Aufbau principle states that electrons fill lower energy levels first and higher energy levels last.
- 🧊 Energy levels overlap starting from the third level, making the order of filling orbitals confusing without labels.
- 🔍 Helium is temporarily considered part of the second group on the periodic table for electron configuration purposes.
- 🔢 The energy levels are labeled 1 through 7, indicating the primary levels where electrons reside.
- 🟧 The periodic table is divided into blocks: the S block (first two columns), P block (right side), D block (middle), and F block (bottom).
- 🪜 The order of electron filling starts at 1s, then 2s, 2p, 3s, 3p, and continues in a specific sequence influenced by energy levels.
- ⚠️ Due to orbital overlap, the 4s orbital fills before the 3d orbital because 4s has lower energy.
- 📉 The F block elements, found in the bottom two rows, have less focus since they are radioactive and not part of typical chemistry studies.
- ✅ The main takeaway is that labeling the periodic table helps identify the correct sequence for electron configurations, which follows the Aufbau principle from left to right and down each row.
Q & A
What is the Aufbau principle?
-The Aufbau principle states that electrons fill orbitals from low energy to high energy, starting with the lowest available energy level before moving to higher ones.
Why is helium penciled in as part of the second group on the periodic table?
-Helium is temporarily penciled into the second group of the periodic table because it helps with organizing electron configurations, even though it belongs to the noble gases in Group 18.
How are energy levels labeled on the periodic table?
-Energy levels on the periodic table are labeled as 1, 2, 3, 4, 5, 6, and 7, corresponding to the principal quantum numbers that describe the different energy levels electrons can occupy.
What does the S block on the periodic table represent?
-The S block on the periodic table represents the first two columns, where all elements have their outermost electrons in S orbitals.
How do you identify the P block on the periodic table?
-The P block includes the elements in Groups 13-18 (excluding helium). It is found on the right side of the periodic table and includes elements whose outermost electrons are in P orbitals.
What is the D block, and where is it located on the periodic table?
-The D block, located in the center of the periodic table, includes transition metals. The outermost electrons of these elements are in D orbitals.
What is the significance of the F block on the periodic table?
-The F block includes the lanthanides and actinides, which are elements located below the main body of the periodic table. These elements have their outermost electrons in F orbitals.
Why does the 4S orbital fill before the 3D orbital?
-Although the 3D orbital belongs to the third energy level, the 4S orbital has a lower energy, so it fills before the 3D orbital due to orbital overlap.
What is the electron filling order for energy levels and sublevels?
-The order is 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p.
Why is less focus placed on the elements in periods 6 and 7, particularly the F block?
-Elements in periods 6 and 7, especially in the F block, are typically radioactive and do not participate in the types of chemistry that are usually studied in detail, so they are less emphasized.
Outlines
🔬 Understanding Electron Configurations and the Aufbau Principle
This section introduces the Aufbau Principle, which explains how electrons fill orbitals starting with the lowest energy level and progressing to higher ones. The speaker discusses the complexity of electron configurations once the third energy level is reached, where orbital overlaps occur. To make this process clearer, labels are added to the periodic table. The first step is to pencil in helium as part of the second group and ensure the energy levels (1-7) are labeled. The speaker also suggests blocking off different regions (S, P, D, and F sublevels) on the periodic table to help understand the electron configuration sequence.
🧪 Electron Configuration Sequence and Overlaps
This section describes the sequence in which electrons fill orbitals based on their energy levels. The process starts with the 1s orbital, followed by 2s, 2p, 3s, and 3p orbitals. A key point is the energy overlap between 4s and 3d orbitals, where 4s is filled before 3d despite being part of the higher fourth energy level. The speaker guides the viewer through labeling these sections on the periodic table, helping to clarify the order of electron configurations. The discussion also touches on the later periods, emphasizing that the lower part of the periodic table (especially the F block) involves radioactive elements, which are less relevant to the chemistry being studied.
Mindmap
Keywords
💡Aufbau Principle
💡Energy Levels
💡Sublevel
💡Periodic Table
💡Helium
💡Electron Configuration
💡Overlap of Orbitals
💡S Block
💡D Block
💡F Block
Highlights
Introduction of the ALB principle, which states that electrons fill low energy levels first and high energy levels last.
Clarification that the first energy levels (1, 2, 3) are filled sequentially, but overlap occurs after the third energy level, causing confusion.
The importance of labeling helium as part of the second group on the periodic table.
Instructions for marking energy levels (1 through 7) on the periodic table to better understand electron configuration.
Using Sharpies or highlighters to block off the S, P, D, and F sublevels on the periodic table for easy reference.
Electrons first fill the 1s sublevel, followed by the 2s, 2p, 3s, and 3p sublevels.
Explanation of orbital overlap: the 4s sublevel is lower in energy than the 3d, so electrons fill the 4s before the 3d.
Step-by-step guide for labeling the periodic table to help track the electron filling order for sublevels, including the 3d and 4p groups.
Discussion on how after the 6s sublevel, electrons move to the 4f block before continuing with the 5d sublevel.
Labeling the F block elements at the bottom of the periodic table for periods 6 and 7.
The final electron configuration order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p.
Reassurance that understanding the filling order in periods 6 and 7 is less critical, as these elements are primarily radioactive and not studied in-depth in chemistry.
Focus is mainly on understanding the electron configuration of elements from period 1 to period 5 on the periodic table.
Encouragement to have the periodic table fully labeled before proceeding with more advanced lessons.
Concluding advice to watch the next vodcast for further instruction on how to apply this electron configuration information in future lessons.
Transcripts
what I'm going to go over in this
vodcast is how we got all those labels
on our periodic table in electron
configurations there's this rule called
the albal principle and the ALB
principle says that electrons like to
fill low energy first and high energy
last so when we talk about filling low
energy first we're talking about the
first energy level the second energy
level the third energy level but the
problem is once we get into the third
energy level orbitals start to overlap
and the order can get a little confusing
by putting labels on our periodic table
it can tell us exactly which order to
follow so we know what to do when we're
doing our configurations so the first
thing that you want to do is on your
periodic
table I would like you to pencil in a
helium right here so we're going to draw
helium in there we're not going to erase
it on the other side but we want to
pencil it in there because we're going
to count helium as part of this second
group on our periodic table for the time
being
and then the next thing you want to do
is make sure that you have the energy
levels labeled um on your periodic table
these numbers are most likely already
there my periodic table is going to look
slightly different than yours but the
energy levels would be 1 2 3 4 5 6 and 7
those would be the energy levels the
next thing I would like you to do is
block off the Su levels so the first
thing we'll
do is we're going to draw draw a
box around the S
subel so if you grab those first two
columns and you can take some Sharpie
markers if you have some or any kind of
highlighter that'll work on your
periodic table and block that off and
label that as the S suble all the
elements in this block are in the S
suble and then if you want to you can
switch
colors and come over here
and we're going to label the S
block so we're going to go right along
here excluding
helium down the side grab those guys on
the bottom
row and we're going to label that as the
P
block and then if you want to switch
colors
again we can label the D
Block which would be in the
middle and then the F
block would be the elements down at the
bottom
here so pause the vodcast for a minute
and go ahead and make sure you have
those labels on your periodic table
before we move on
all right now that you've done that what
we'll look at is the order in which the
electrons fill these orbitals the first
place that electrons are going to go is
into the 1s subl we call this the 1s
because it's the first energy level S
Sub
level the second place electrons are
going to go is into the 2s second energy
level s subev if you then come across
the periodic table the next group that
you run into would be called 2 p 2 p
because this is the second energy level
and the P
suble so we have 1s 2 s then we come
across 2 p you read this just like you
would a page in a book left to right
down the page then the electrons would
go into the
3s and the 3p again this is called 3p
because third energy level P sub level
now you would expect 3D to come next
however
this is where the overlap occurs where
the 4S is actually lower energy than the
3D so we would call this group the 4S
but then right here we would want to
label this
group as the 3D row so if you stick that
label on your periodic table that'll
help remind you that this row is called
the
3DS then we have the four
Ps in the next row we would start with
5S again fifth energy level s suble so
this would be the
5S this group would be called the
4ds this is still the five PS the only
place that it's offset is here in the
middle the sides are still the
same then we would come down to the 6s
you would expect the 5D to come next
however if you look at the atomic
numbers 55 56 57 58 59 60 you realize we
got to jump down here first before we do
the five D's so after the 6s we would
label this section as the 4
FS okay all the way down the line then
look 69 70 71 number 72 is back up here
so we're going to label this group the 5
D's then we have the 6
PS
7s and then 87 88 89 90 so we're going
to come down here and label this group
the 5
FS 100 101 102 103 104 is right here
these would be called the
6d's and then the 7 PS so the order that
we follow for electrons to fill orbitals
is just across and down the periodic TBL
so we do 1 S 2
S 2
p 3
S 3
p 4S
3D 4
P
5S
4D 5 P 6s then we come down to 4
FS
5D
6p and then the last row
7s
5f 6D and 7p you really don't have to
stress over the order too much down here
when we get to um period 6 and 7
um in the F block down here because
those elements don't undergo the
chemistry that we're going to study
anyway those are all radioactive so most
of our focus is going to be kind of from
here on up in the periodic table we go
through this so what you want to do at
this point is make sure you have all of
these labels on the periodic table and
then check in with the next vodcast and
that'll give you the lesson that we
follow after that
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