Grade 9 Chemistry, Lesson 6 - The Periodic Table - Part 1 - Free Educational videos for Students in K-12

Grade 9 Chemistry, Lesson 6 - The Periodic Table - Part 1 - By Lumos Learning

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00:0-1	Hey , everyone , this is Mr Lee Han teaches
00:01	you stuff . This is Grade nine chemistry lesson six
00:04	The periodic table , part one . So this is
00:51	what the periodic table looks like , and it has
00:53	every single element that we have ever found in the
00:56	universe . It is on this table , and this
00:59	table is arranged in a very specific order . If
01:03	you look down at the bottom , you'll see that
01:06	there's a box that's somewhat separate from the rest of
01:08	the table . Um , starts off with number 57
01:12	number 89 right underneath it . That box is actually
01:15	supposed to be part of the rest of the table
01:18	, and if it's if it's put in where it's
01:20	supposed to be at the table , actually looks like
01:43	this . So this is what the periodic table should
01:46	look like . But we just take those two rows
01:49	out and shove them underneath the periodic table just so
01:53	it fits on pieces of paper or posters that you
01:56	put up in a classroom . Easier . But this
01:58	is this is the actual look of how the elements
02:02	should be arranged on the periodic table . Now I'd
02:34	like to go over a little bit of the history
02:36	of the periodic table . Early on , scientists tried
02:39	to organize the elements into some groups or order ,
02:42	but ran into several difficulties . They couldn't arrange things
02:45	alphabetically because every time they found a new element ,
02:49	they'd have to rearrange the entire list . So alphabetical
02:53	order didn't seem to work . They couldn't organise things
03:27	by color because so many of them look the same
03:30	. So here's a several elements here , and they
03:34	all look pretty much the same . You wouldn't have
03:36	a hard time figure out which one's which just by
03:37	looking at them . They also couldn't use taste to
03:41	discriminate between the elements because many of them were quite
03:44	poisonous . You tasted , some of them would just
03:46	die . Then along came a Russian scientist named Mandalay
04:21	Ev , and he found that if you arrange the
04:23	elements based on their chemical properties and their atomic mass
04:27	, a pattern emerged . So Mandalay have used his
05:11	knowledge to create a periodic table , and he even
05:14	left spots open where he knew other elements should exist
05:17	because an element with certain properties of a certain mass
05:20	had not been found yet . So , for example
05:23	, Element 31 right here , gallium gallium had not
05:27	been discovered when Mandalay have made his table , but
05:30	he left a spot open for it because he knew
05:32	there should be something . There have a certain weight
05:35	with certain properties , and he was able to correctly
05:38	predict its atomic mass , its density , its melting
05:42	point and how it would react with other chemicals before
05:46	anyone else even knew this thing existed . So this
05:49	is a big deal because scientists have not been able
05:51	to make predictions about undiscovered elements before . So when
05:55	Mendeleev did it , it seemed almost magical , and
05:58	everyone quickly adopted the periodic table . Now we are
06:02	still filling in blanks of the periodic table today ,
06:05	Um , on May 30th , 2000 and 12 ,
06:08	2 elements were added to the periodic table , so
06:13	number 1 14 and 1 16 Flora Veum and Liver
06:16	Mori um , were added in 2000 and 12 .
06:19	So if you look at this periodic table and you
06:21	compare it to one that's probably hanging in a science
06:24	classroom , you might notice that this one has more
06:28	elements in it . And that's because a lot of
06:30	the older periodic tables are rather out of date .
06:33	So this one's up to date as of right now
06:37	, in 2013 , um , they are . So
06:53	we're still filling in the blanks of the periodic table
06:56	. And if you look down at the bottom right
06:58	hand of the table , you'll see several elements seem
07:03	a little out of place . These ones have three
07:05	letters in their chemical symbol instead of one or two
07:09	, and these are just placeholders . These ones have
07:11	not actually been found . So 1 13 is an
07:16	entry . Um , which stands for 113 e .
07:20	M . 1 15 is onion Pentium , which stands
07:25	for 115 p . M . 1 17 is unacceptable
07:33	, which is 117 p . M . And 1
07:37	18 is una noche de um , which , of
07:39	course , is 11 80 m . So I'm sure
07:42	you get the pattern there . Uh , keep in
07:45	mind that these are just placeholders . We haven't actually
07:47	find these periods in real life in each box .
07:50	Once we do , we have , they'll get a
07:52	proper and atomic number , which remember is that we'll
07:54	get rid of the three letter chemical symbol For those
07:57	. There's the chemical symbol right there . There's the
08:02	element name underneath the chemical symbol . There we have
08:07	the atomic mass , which remember , is the number
08:09	of protons plus the number of neutrons . And we
08:13	also have the ion charge up at the top ,
08:17	right ? So if you want to know how many
08:39	protons and element has , all you have to do
08:42	is look at the atomic number . So in this
08:44	case , 17 . If you want to know how
08:48	many electrons and element has , it's the same as
08:51	the number of protons and the atomic number , so
08:54	the number of electrons is 17 . If you want
09:29	to figure out how many neutrons there are , you
09:32	need to take the atomic mass . That's the big
09:34	number and subtract the atomic number , which is the
09:37	smaller number . So just remember big number minus smaller
09:41	number , and you'll be good . So we take
09:45	35.45 which we round up to 36 and then we
09:51	subtract 17 and we end up with 19 neutrons .
09:56	So chlorine has 19 neutrons , so let's do a
10:22	couple more examples . How many protons , electrons and
10:25	neutrons does boron half , while Baron has an atomic
10:29	number of five , which means it has five protons
10:33	, it also means it has five electrons . Next
10:37	, we can look down here . It has an
10:39	atomic mass of 10 91 We need to round that
10:43	up to 11 . So we take 11 minus the
10:47	five protons , and we end up with six neutrons
10:51	. Soberon has five protons , five electrons and six
10:55	neutrons . I will do one more example . How
10:59	many protons , electrons and neutrons does cobalt have while
11:03	cobalt has an atomic number of 27 so it has
11:07	27 protons and 27 electrons . Now Cobalt also has
11:13	an atomic mass of 58 decimal 93 So we'll just
11:17	round that up to 59 . And then we do
11:20	59 minus 27 that gives us 32 neutrons . So
11:26	I just want to point out that we don't use
11:27	the ion charge in the top right there . That
11:30	two . Plus , we don't use that at all
11:32	to calculate the number of neutrons . So cobalt has
11:35	27 protons , 27 electrons and 32 neutrons . So
11:41	now let's take a look at chemical symbols . Chemical
11:44	symbols always consist of either one or two letters .
11:48	Now the first letter is always capitalized , and the
11:50	second is always lower case , and this is to
11:53	prevent confusion . So , for example , C O
11:58	does not equal c o . The first CEO .
12:01	There . You've got capital C Capital O . That's
12:03	carbon and oxygen , and that's carbon monoxide . And
12:07	it does not equal capital C little o or lower
12:11	case O , because that's an element that's cobalt .
12:15	So carbon monoxide is not the same as Cobalt ,
12:19	since there's lots of elements out there with the same
12:21	first letter in their name . Some use letters from
12:25	their Latin name instead . So let's go through a
12:29	few examples where the chemical symbols are very different from
12:32	the name of the element . So first off ,
12:36	we have H G , which is mercury symbol ,
12:38	and that H G comes from the word hydrogen here
12:42	, um , which is Latin for liquid silver .
12:45	So if you ever see mercury , it looks like
12:47	basically liquid silver . Um , Silver , on the
12:52	other hand , is a G , and that egg
12:56	comes from the Latin , our gente um , which
12:59	means silver au is gold symbol and the way you
13:06	comes from the word or um , which is Latin
13:09	for gold . Now sodium . Its symbol is an
13:14	A , and then a comes from the atrium ,
13:18	which is Latin for sodium . And now atrium actually
13:22	comes from the French word neutron , which is basically
13:26	baking soda and baking soda contains sodium . So that's
13:32	how it all sort of mixes together there . Yeah
13:35	, PB is lead , and the PBY comes from
13:39	Plum Bomb , which is Latin for lead . Actually
13:43	, sorry that's not Latin for like , it's Greek
13:45	for lead . And the Greeks used to use led
13:48	to make their pipes . And that's also where we
13:50	get the word plumber from and last example is F
13:55	E . That's iron symbol , and Effie is where
14:00	it comes from Farum , which is Latin for iron
14:05	. So how is the periodic table arranged ? Each
14:07	element has an atomic number that represents the number of
14:11	protons , and Adam of that element has . So
14:13	we knew that already . But as you go left
14:15	to right across the road , the atomic number increases
14:18	by one for each element . So the first element
14:21	at the very top left hydrogen . It has one
14:24	pro time second element with the atomic number . Number
14:28	two , it has two protons and then three protons
14:33	. 45678 It goes up like that . So that's
14:36	how these things are arranged . So that's it for
14:38	this video tune into our next video , the periodic
14:41	table part two patterns in the table

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