Atoms Simplified - Bohr Models & Lewis Dot Structures

Summary

Highlights

• Bohr Models help simplify atomic drawing by only showing electron shells and omitting the nucleus for clarity ☝️.
• Lewis Dot Structures further simplify atoms by focusing only on valence electrons, which play a key role in bonding ✨.
• Kyle Dunn explains how periodic table positions reveal the number of valence electrons for easier visualization 🗺️.
• The lesson offers practical examples using elements like hydrogen, helium, carbon, and more to illustrate Bohr Models and Lewis Structures 🧪.
• This approach to teaching makes complex atomic theory more accessible and engaging for learners 🚀.

Key Takeaways

• Bohr Models simplify atom structures by focusing on electrons in energy levels, making atoms easier to visualize and draw 🎨.
• Lewis Dot Structures reduce complexity further by only showing valence electrons, crucial for chemical reactions 🌟.
• Understanding energy shells and electron configurations is key to depicting atoms accurately and understanding their behavior 🔍.
• The number of valence electrons can be determined from an element's position on the periodic table, aiding in quick visualization 🧠.
• This lesson sets up the foundation for learning about compounds and chemical bonding in future lessons 🔮.

Overview

Atoms Simplified - Bohr Models & Lewis Dot Structures Transcription

• 00:00 - 00:30 all right guys in our last lesson we looked at how to build atoms using the recipe on the periodic table of elements now let's look at simplifying those atoms so that they are more useful and quicker to draw so here's our typical atom uh this is a carbon atom it's got six protons six neutrons and buzzing around in two different energy levels six electrons but an atom doesn't really look like this
• 00:30 - 01:00 it looks more like this kind of this fuzzy hazy ball of electrons swirling around a teeny tiny superdense little nucleus so why do we use this instead quite simply it's just easier for us to understand we can kind of put our finger on each little particle in there and make sense of that so to make it even easier we're going to use board diagrams four diagrams were created by
• 01:00 - 01:30 this scientist right here Neil bore he was a particle physicist and very famous he realized that we could simplify the drawing of the atom so that it makes sense it doesn't have to be accurate it just has to represent something real so here's a carbon atom uh kind of in a traditional format if we want to simplify it into a board diagram it would look something like this instead much simp simpler smaller easier to
• 01:30 - 02:00 write so let's look at some of the basics of drawing board diagrams first we're going to get rid of the nucleus and replace it with our element symbol instead in this case C for carbon next we're only going to include the electrons and their energy shells not the protons or neutrons carbon has two energy shells so we're going to put two energy shells around our our C and then lastly we're going to draw our electrons as little dots rather than little negative signs or little explosions or
• 02:00 - 02:30 circles or anything like that all right so in order to draw board diagrams correctly you have to understand the energy shell rules we went over this in the last lesson that is 2 N squar where n equals the shell number so in the first shell we're going to have two electrons in the second 8 third 18 and so forth and we're going to fill up our first shell before we move on to the second and then fill up the second before we move on to the third all right so let's start out building hydrogen really simple it's one
• 02:30 - 03:00 proton and one electron all right on the periodic table hydrogen Falls in Period number one that is row number one which means it only has one energy shell to draw our board diagram we know that we're going to use an H for hydrogen and we're going to draw just one circle on it representing one energy shell now we've only got one electrons we're just going to stick one dot on there now let's do helium helium also falls in Period number one or Row one so it's just going to have one energy shell
• 03:00 - 03:30 here we're going to draw helium as H for the nucleus and draw one energy shell helium has two protons therefore it's going to have two electrons so we're going to put each electron on that first energy shell 1 two now let's look at burum burum Falls in row number two or period two which means it's going to have two energy shells so for burum we're going to put be for our nucleus and we're going to surround that by two energy shells one
• 03:30 - 04:00 two now it's going to have four electrons but only two fit in the first shell so we're going to put those in there 1 2 8 fit in the second energy shell but we're only left with two more so we're just going to put two more in there 1 two for a total of four electrons let's do something more complex oxygen oxygen is in Period two so oxygen is only going to have two energy shells so oxygen o for the nucleus one two energy shells now we have eight
• 04:00 - 04:30 electrons two in the first shell 1 two and we're going to have eight in the second shell but we've only got six left over because we've already got two in the first shell so we're going to put six electrons 1 2 3 4 5 six in our second energy shell for a total of eight electrons let's look at sodium sodium fits in the third period or third row so it's going to have three energy shells here's sodium na with 1 2 three
• 04:30 - 05:00 energy shells now we're going to have 11 electrons two in the first shell 1 2 the second shell holds eight so let's put all eight in there 1 2 3 4 5 6 7 8 that's a total of 10 so our third energy shell is just going to have our one leftover at or electron one so that a total of 11 electrons lastly let's do aluminum aluminum fits into the third period so it's going to have three
• 05:00 - 05:30 energy shells Al for the nucleus one two three energy shells 13 electrons two in the first shell eight in the second shell for a total of 10 and then we've got three more that need to fit in our third and outer energy shell 1 2 3 there are some Bard diagrams but we can go simpler and we can do that with
• 05:30 - 06:00 Lewis Dot structures all right so it was realized at one point that board diagrams were great but even they were a little too cumbersome because really it was those outer electrons that did most of the chemical reacting in elements so for LS dot structures we kind of got rid of all of the electrons and focused just on the ones on the outside instead so a l dot LS Dot Structure would look something like this there is a c carbon
• 06:00 - 06:30 and four dots for four outer electrons all right so the Lou dot Basics go as follows stop drawing all of the energy shells it's unnecessary we just need to focus on the outer energy shell so we're only going to include what are called veence electrons we'll go over that in just a second and we're going to draw electrons as little dots around the element symbol but not put on energy shells all right so we need to understand first what veence electrons are and it's pretty simple veence electron are just the electrons that we
• 06:30 - 07:00 find in the outermost energy shell of an atom so if an atom only has one energy shell it's that energy shell that has veence electrons if it has three energy shells it's going to be energy shell number three that contains the veence electrons okay so here are veence electrons in perum just the outer two sodium just has one veence electron in the third energy shell and hydrogen has one and it's one energy shell so the outer shell is what we call
• 07:00 - 07:30 the veence Shell the outermost energy shell of an atom and the outermost energy shell just depends on how many energy shells you've got if you've got two like pilum it would be shell number two if you've got one like hydrogen it would be shell one and if you have three like sodium it would be shell number three that would be the veence shell so in board diagrams what we do is we get rid of any inner shells and inner electrons and focus just on the outer so let's start up at the top left with Hydro
• 07:30 - 08:00 to make a leis Dot Structure of hydrogen we're going to get rid of our energy shell and we're going to bring that one veence electron down closer to our symbol for helium same deal going to get rid of that energy shell and we're going to bring just our two outer electrons in closer to the helium all right burum is a little different we're going to eliminate our energy shells but and we're going to drop those two on the inside because those were the inner energy shell not the outer and we're only left with two in the outer we're
• 08:00 - 08:30 going to bring those in close for oxygen we're going to eliminate our energy shells and we're going to eliminate the electrons on the First Energy shell as so that leaves us with six electrons in the veence Shell which we're going to bring in close to our symbol to make our leis Dot Structure check out this sodium now we're going to eliminate three energy shells all of the electrons on the first two leaving just our single electron on the outer shell which we're going to bring in close that is much much simpler
• 08:30 - 09:00 than our previous boore diagram and finally with aluminum same thing eliminate our energy shells eliminate all the electrons in the first two leaving just the outer energy shell electrons for aluminum so take a look at these Lewis Dot structures much simpler much much simpler than the board diagrams last thing I want to leave you with is that if we look at the periodic table of elements we can figure out how many veence electrons would be in our leis dot structures pretty easily for
• 09:00 - 09:30 example from hydrogen on down every element in that column has one veence electron from brillium on down they all have two from Boron on down they all have three carbon down has four nitrogen and down has five oxygen and down has six Florine and down has seven and finally on the very last column to the right they all have eight with the exception of helium because helium only
• 09:30 - 10:00 has two but its outer veilance shell is considered full so it's actually just two all right guys next time we're going to use these board diagrams and leis dot structures to make ourselves some compounds