0:03 the topic of this video is the periodic table
0:03 table
0:05 the learning objectives are on your
0:07 screen before jumping into the modern
0:10 view of the periodic table it's
0:12 worthwhile to mention briefly the some
0:15 historical aspects of the periodic table
0:18 the person shown in the figure on the
0:21 left is dimitri mendeleev he is largely credited
0:23 credited
0:27 for inventing the periodic table
0:29 another scientist around the same time
0:32 named lothar meyer in germany
0:35 is is also credited with independently
0:37 recognizing that there
0:40 were periodic relationships among
0:42 properties of elements
0:44 at that time although mendeleev by far
0:46 gets the most recognition
0:50 um it's it's remarkable to think that
0:53 uh at the time this is the late 1800s so
0:54 this is before
0:58 the likes of of um
1:02 einstein and max plunk and
1:06 de broy and schrodinger uh before
1:08 the the the advent of quantum mechanics and
1:09 and
1:12 and wave particle duality and
1:15 electron configurations before
1:20 those um concepts had been crystallized
1:24 um scientists such as mendeleev
1:28 and both our meyer were able to
1:30 categorize elements based off of their properties
1:31 properties
1:34 to to and it was so successful that they
1:34 could actually
1:37 predict missing elements that had not
1:39 yet been discovered
1:41 but again these were the the original
1:43 periodic table was created
1:46 to list elements by their
1:49 similar properties not necessarily by an
1:51 atomic number or valence electrons or
1:54 anything along those lines
1:56 now we can jump forward to the modern
1:58 periodic table which is on your screen
2:02 and also the periodic law the periodic
2:03 law states that the properties of the elements
2:04 elements
2:06 are periodic functions of their atomic
2:09 numbers so this
2:12 gives us a more concrete way to organize
2:13 elements in the
2:19 i should point out here that in an
2:21 earlier video
2:24 i had mistakenly referred to the vertical
2:25 vertical
2:29 columns as periods whereas the vertical
2:30 columns here
2:33 in the periodic table are groups okay so groups
2:35 groups
2:38 are the columns running up and down the
2:39 the periodic table
2:43 and then the periods are actually the
2:46 rows okay so here we have
2:49 seven periods in the modern periodic table
2:50 table
2:54 and we have 18 groups
2:56 okay so i just thought i'd point that
2:58 out in the electron configuration video
3:01 i was mistakenly calling groups periods
3:03 and i guess that's just a good lesson it
3:05 can be easy to get these mixed up
3:08 so come up with some sort of um
3:11 strategy to to make sure that you can
3:12 remember which are which
3:14 but oftentimes it's it's labeled in a
3:15 periodic table so
3:18 maybe i don't have an excuse we can also
3:20 look at different
3:23 element types so down here is a color code
3:24 code
3:26 for metals metalloids and nonmetals what
3:28 you'll notice is that
3:30 the vast majority of elements in the
3:32 periodic table that i'm circling
3:35 now fall within the
3:38 metal category so
3:40 the vast majority of elements that we know
3:41 know
3:45 are actually metals this pink
3:48 uh region in between i'll maybe change colors
3:48 colors
3:52 to here this this area here
3:56 between metals and non-metals it has
3:59 elements that we refer to as metalloids
4:00 they have characteristics that are
4:03 somewhat metallic but also somewhat non-metallic
4:04 non-metallic
4:08 um and then in the green we have the
4:09 nonmetals and that's
4:12 including hydrogen over here
4:15 maybe i'll change color one more time
4:19 so uh over here we have our
4:22 non-metals okay
4:26 so yeah one way to to remember
4:29 um the the this division between metals
4:31 metalloids and nonmetals is to
4:34 um memorize the metalloid elements and
4:36 you can remember that those elements to
4:37 the left
4:39 are going to be metals and those to the
4:41 right in the main group are going to be nonmetals
4:43 nonmetals
4:47 um so we can also assign some names
4:50 to break down the main group elements a
4:52 little bit more
4:54 here i'm going to change my color yet
4:56 again okay
5:00 so uh we have looked at main group
5:03 elements before but now group one we're
5:04 going to define
5:07 as um alkaline metals
5:09 okay so group one are alkaline metals
5:11 these are things like sodium
5:14 and lithium and even hydrogen and these
5:16 tend to form
5:20 plus one cations because they can
5:22 they can readily lose one electron they
5:23 have low first ionization
5:25 energies they can lose one electron and
5:27 they ultimately want to get to that
5:30 to this noble gas electron configuration
5:33 by losing one electron alkali earth
5:35 metals have two electrons in their
5:36 valence shell
5:39 that's what you unifies their uh uh
5:40 chemical characteristics
5:43 so they tend to form plus two cations
5:44 this is the
5:48 these are uh elements like magnesium and
5:50 calcium okay so this is group two
5:53 alkali earth metals plus two cations
5:55 and uh keeping in mind that when they
5:56 lose both electrons in their valence
5:58 shell they will end up with the noble
6:00 gas configuration
6:02 if we jump over here to nicotines in group
6:04 group
6:07 15 this is now going to be things like
6:10 nitrogen and phosphorus these can readily
6:11 readily
6:15 gain electrons and they can
6:19 form sort of i'll say
6:22 as an example n three minus you know
6:24 they can accept up to three electrons
6:26 in order to achieve that noble gas configuration
6:28 configuration
6:33 um calcogens his next and group 16.
6:36 uh would be things like sulfur and oxygen
6:37 oxygen
6:39 so these can gain two electrons they're
6:41 only two
6:43 groups away from the noble gas
6:44 configuration so they tend to gain two electrons
6:45 electrons
6:47 halogens you might see the the general
6:49 theme here halogens something like fluorine
6:49 fluorine
6:52 or chlorine can accept one electron to
6:54 get the noble gas configuration
6:57 noble gases are considered noble because
6:59 they are relatively inert
7:01 we've already covered transition metals
7:03 and also
7:06 d-block metals and then also lanthanides
7:08 and actinides as the inner transition metals
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