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00:00:08
Hello everyone My name is Anastasia Mayer I00:00:11
am a chemistry teacher at the00:00:12
online school Umskul and specifically in this00:00:14
video we will discuss such a topic00:00:16
as crystal lattices and at the same time00:00:18
learn how to solve the fourth task of the Unified State Exam00:00:21
dedicated to this topic Before we00:00:23
begin I would like to clarify what is in the description To00:00:25
this video I also added links to00:00:27
previous videos of a similar format.00:00:29
Therefore, if you don’t want to memorize00:00:31
chemistry but really understand this subject,00:00:33
be sure to follow the links in00:00:35
the description of this video and watch the00:00:37
previous videos to pass the Unified State Exam with00:00:40
high scores, first let’s clarify00:00:42
with you that everything substances can, in principle, be00:00:44
divided into two large categories:00:00:46
amorphous substances and00:00:48
crystalline substances, amorphous substances are00:00:50
those that essentially do not have a00:00:53
definite structure; the particles in them00:00:55
have a clear order, one00:00:58
particle there, another here, a third one a00:01:00
kilometer away from them, and because of this00:01:02
chaos in the arrangement of particles,00:01:04
amorphous compounds do not have any00:01:06
clear temperatures and other clear00:01:09
tabular indicators, another00:01:12
thing is that these substances are crystalline, in00:01:13
fact, they are their complete opposite00:01:15
because in crystalline substances00:01:17
each particle has its own place,00:01:19
you feel there is a certain structure in the00:01:22
arrangement of particles there is a clear order00:01:25
thanks to this clear order,00:01:28
crystalline substances00:01:30
have clear melting points and00:01:32
other tabular indicators. Today we00:01:35
will talk to you in the00:01:36
fourth task of the Unified State Exam specifically about00:01:38
crystalline substances, as we00:01:41
told you earlier in crystalline00:01:43
substances we observe absolute00:01:45
order in the arrangement of particles each00:01:47
particle has its own place, essentially this00:01:50
very order in the arrangement of particles is00:01:52
called a crystal lattice00:01:54
again Let's say what it is, essentially a00:01:56
crystal lattice is a00:01:58
spatial frame in which the00:02:00
particles are located, a crystal00:02:03
lattice essentially shows us how these00:02:05
particles are located in a crystal00:02:08
and accordingly the very places in which00:02:10
these very particles are located are called00:02:12
nodes of the crystal lattice because00:02:15
what particles we have are located at the nodes of00:02:18
our crystal lattice and00:02:19
there are four types in total. So let’s look at00:02:22
each of them first simply by00:02:25
name So the types of crystal00:02:27
lattices00:02:29
the first is actually a metal00:02:32
crystal lattice00:02:36
the second the type of crystal lattices is00:02:39
ionic00:02:41
[music] the00:02:42
third atomic00:02:45
and the fourth type of crystal lattices00:02:48
is the molecular crystal lattice00:02:50
[music]00:02:53
I think, in principle, from the names of the00:02:55
crystal lattices it is clear what is00:02:57
located in their nodes, for example, in the00:02:59
nodes of the ionic crystal lattice00:03:01
there are ions of charged particles00:03:03
located in the atomic nodes atoms And in the00:03:05
nodes of the molecular, respectively,00:03:07
the molecule, here’s a small spoiler00:03:09
in advance So what do you and I need to00:03:12
know about each of the types of00:03:13
crystal lattice, but the first thing is00:03:15
that we have already said what is located in the nodes of00:03:17
each crystal lattice, this is as00:03:20
we understand it is clear from its name the second00:03:22
This is what substances this00:03:24
type of crystal lattice is characteristic of. And the third,00:03:26
accordingly, is what00:03:28
physical and some chemical properties00:03:30
do substances with this type of00:03:33
crystal lattice have, but00:03:35
we’ll talk about everything in more detail now.00:03:37
So the first type of00:03:40
crystal lattice, as I said, is00:03:42
metallic crystalline lattice00:03:43
as It is clear from its name that the nodes00:03:46
contain particles such as atoms and00:03:49
metal ions. Let’s immediately write down00:03:53
what properties will be characteristic of00:03:57
all substances that have a00:03:59
metal crystal lattice,00:04:01
that is, for metals. Let’s remember00:04:03
for this purpose any00:04:04
average metal. Well, first of all00:04:06
metals are usually solid substances00:04:09
in their state of aggregation, the00:04:11
only exception is mercury, which is liquid under00:04:13
normal conditions, let’s write this down right away, that00:04:16
is, the first property is a00:04:19
solid state of aggregation,00:04:22
the second, respectively, their general properties.00:04:24
We can remember from00:04:27
personal experience. Probably each of you at00:04:29
some point for example, I fried myself some eggs00:04:33
and then accidentally touched the00:04:35
frying pan in which all this happened00:04:37
here and you can accordingly remember the00:04:40
second property, as I already said, this is00:04:43
that metals are excellent conductors of heat and00:04:45
they are also excellent conductors of electricity, but00:04:47
let us check this from personal00:04:49
experience Let’s not So, the second00:04:52
property of substances with a metal00:04:54
crystal lattice is good00:04:57
heat and electrical conductivity. The00:05:05
following property that we can00:05:07
remember regarding metals is,00:05:09
accordingly, that they00:05:13
can melt at a certain heating00:05:16
and subsequently00:05:18
we can give the necessary00:05:21
form which they will retain, this00:05:23
property is called plasticity or00:05:25
malleability in this case, you can, for example,00:05:27
remember the same Blacksmiths who00:05:29
forged various devices from metal and other metals,00:05:32
that is, we00:05:35
heat the metal. Yes, it melts or00:05:38
becomes softer, more pliable,00:05:40
and with the help of this we can give it the00:05:42
specific shape we need.00:05:45
subsequently will retain this and00:05:47
is called plasticity or malleability,00:05:50
we will write this also in00:05:56
this way common to all metals,00:05:59
that is, substances with a metal00:06:00
crystal lattice are00:06:02
solid state of aggregation, with the exception of00:06:05
as we said here, mercury is liquid under00:06:07
normal conditions, good00:06:09
conductivity of heat and electricity, that is,00:06:11
good heat and electrical conductivity and00:06:13
plasticity or malleability, the00:06:16
next type of crystal lattice is an00:06:18
ionic crystal lattice, as I00:06:21
think. It is clear from the name that its nodes00:06:23
contain particles such as00:06:25
positively charged or negatively00:06:27
charged ions.00:06:29
For what substances will an ionic crystal00:06:32
lattice be characteristic absolutely00:06:34
logically, and for substances that00:06:36
contain there are ionic bonds, let me00:06:38
remind you a little about the topic of00:06:41
chemical bonds, ionic bonds are00:06:42
usually realized between a metal and a00:06:45
non-metal by the opposites plus and00:06:47
minus, relatively speaking, for example, they are a00:06:49
compound sodium chlorine, we see a bond with a00:06:51
metal non-metal potassium 2co3 barium o00:06:55
lithium OH and others, that is, metal-00:06:58
nonmetal bonds and sinful chemistry in our country00:07:00
are always ionic. And if there are00:07:03
ionic bonds in a compound, then this is a connection of an00:07:05
ionic structure with an ionic crystal00:07:07
lattice. That is, everything is completely00:07:09
interconnected. I also remind you that00:07:11
ionic bonds also exist in00:07:13
ammonium compounds, that is, particles of nh4 + and00:07:16
its various analogues in organic00:07:19
chemistry we summarize with you in this way00:07:22
For what substances will an00:07:24
ionic crystal lattice be characteristic? It will be00:07:26
characteristic for substances in which00:07:29
ionic bonds are used, most often00:07:31
a metal or a non-metal, that is, for various00:07:33
salts of metal oxides and hydroxides and00:07:36
ammonium compounds of its analogous00:07:39
substances in organic chemistry. What are the00:07:41
properties of what? the most interesting things will be00:07:43
characteristic of substances with this type of00:07:45
crystal lattice. Well, let’s00:07:47
remember00:07:49
the average statistical salt. Yes, for example, the00:07:51
same sodium chlorine is table00:07:54
salt that each of us has00:07:56
in the kitchen, what can we say about it?00:07:57
Well, first of all, this substance00:08:01
table salt, solid in its state of aggregation, we will write down00:08:05
further. Next, what we can say for sure is00:08:07
that this compound is soluble in water.00:08:09
For example, we can immediately recall how we00:08:12
cook dumplings or pasta and00:08:15
accordingly throw that00:08:17
same ill-fated sodium chloride,00:08:20
sodium chloride, table salt into boiling water; it00:08:21
dissolves perfectly in water, therefore, the second00:08:24
property that we will write down for00:08:26
substances with an ionic crystal00:08:28
lattice is good solubility in00:08:30
water, not all substances with such a00:08:32
crystal lattice are well00:08:33
soluble in water, but many are the00:08:39
following property that again00:08:41
may come to your mind. Perhaps this is00:08:45
that solutions and melts these substances00:08:47
conduct electric current very well,00:08:50
I can give an example from life that00:08:54
some people have probably encountered, if we00:08:56
take two vessels with water, but00:08:59
one water will be ordinary and the second will be00:09:01
salty, that is, the one in which they threw00:09:04
salt, for example table salt,00:09:06
then the salty water will be much it is better00:09:09
to conduct electricity precisely00:09:11
because of the presence of charged particles00:09:13
of ions, respectively, the third properties00:09:16
that we will write down for substances with an00:09:17
ionic crystal lattice is00:09:20
precisely the fact that their solutions and melts00:09:23
conduct electric current well00:09:26
[music]00:09:31
what other interesting things can you00:09:33
remember here for example, this is such a property of00:09:35
table salt as refractoriness, that00:09:38
is, this substance table salt has a00:09:40
very high melting point, in00:09:43
my opinion, about 800 degrees, if my00:09:46
memory serves me correctly, that is, at this00:09:47
temperature table salt turns into a00:09:50
liquid state of aggregation, melts, that00:09:52
is, melts at a very high00:09:54
temperature it melts hard, therefore, a00:09:57
compound of this kind is called00:09:59
refractory and the compound is quite00:10:01
strong, respectively. The00:10:05
fourth property that we00:10:07
will write down in this way is strength and the00:10:09
fifth is refractory.00:10:12
That is, as a rule, such00:10:14
substances have high00:10:18
melting points; they are really difficult00:10:20
to melt. So let's summarize everything00:10:22
that we are here with you wrote an ionic00:10:25
crystal lattice at the nodes of such a00:10:27
crystal lattice it is absolutely00:10:28
logical that ions are located as It is clear from00:10:31
the name that this type of00:10:33
crystal lattice is typical for substances with00:10:34
ionic bonds inside, most often these are00:10:37
bonds metal non-metal sodium chlorine Potassium00:10:40
2co3 bario Lithium OH and so on yes Or00:10:44
for the compound of ammonium and its some00:10:46
similar substances in organic chemistry00:10:48
what properties are characteristic of these00:10:50
compounds this is usually a00:10:52
solid state of aggregation Yes under00:10:54
normal conditions this is good as a00:10:56
rule solubility in water00:10:58
conduction of electricity in solutions or00:11:02
melts due to the fact that they00:11:04
disintegrate there into ions plus and minus00:11:06
strength and refractoriness00:11:08
So, the penultimate type of00:11:10
crystal lattice for today is the atomic00:11:12
crystal lattice as It is clear from00:11:15
the name that its nodes contain00:11:16
particles such as atoms. Let's immediately write down00:11:21
what substances have this type of00:11:24
structure; in fact, the list of these substances00:11:26
for the Unified State Exam is actually not that long and00:11:29
the easiest way to actually remember them00:11:31
is that substances with an atomic00:11:33
crystal lattice include00:11:35
carbon in the form of graphite or diamond,00:11:37
silicon and many of its compounds,00:11:39
for example, silicon oxide and silicon carbide.00:11:42
Boron and red black phosphorus; the list is00:11:46
quite small and can be found in the Unified State Examination00:11:48
just what I wrote00:11:50
right here are what properties00:11:54
do substances with an00:11:56
atomic crystal lattice have in common with each other;00:11:57
respectively, the atoms that are located at the00:12:00
nodes of these crystal lattices are00:12:02
connected to each other by extremely strong00:12:05
bonds, which explains00:12:08
many of the physical and chemical properties of00:12:10
these substances, I propose you can sort them out00:12:13
using the example of the same Diamond, a diamond.00:12:16
It is hard under normal conditions,00:12:17
super strong and a super refractory00:12:21
combination. Yes, Diamond is so strong00:12:23
that it can even cut glass; it is00:12:28
so refractory that it melts00:12:30
only at a temperature of 3.5 to 4,00:12:33
approximately thousand degrees. Based on from this00:12:36
we can formulate with you the first three00:12:38
properties which, in principle, are characteristic00:12:41
of most substances with an atomic00:12:43
crystal lattice. The first is that00:12:46
our substances are solid, as we have already said,00:12:49
in terms of their state of aggregation,00:12:52
strong, we immediately remember Diamond00:12:56
and refractory, that is, it melts at very00:12:59
high temperatures to really melt them00:13:02
heavily00:13:03
refractory, what can we remember, well,00:13:08
actually, Diamond practically does not00:13:11
conduct electric current for us, this is the fourth00:13:13
property and one more thing. You can also say that00:13:16
these are all substances that are quite chemically00:13:19
inert, that is, it is really very difficult to make them interact with someone00:13:24
even if you have00:13:26
a diamond ring and you00:13:29
respectively lower your hand with a diamond00:13:31
ring00:13:32
into a solution of concentrated sulfuric00:13:34
acid with Diamond, believe me, nothing00:13:37
will happen to the prophet, we are now, of course,00:13:39
keeping silent about this is another question, but as a fact00:13:41
nothing will happen to Diamond. This00:13:43
substance is extremely chemically lazy and00:13:46
inert to make it react with someone00:13:48
It’s difficult to00:13:50
formulate the fourth and fifth properties accordingly00:13:52
based on what we said. The00:13:54
fourth property, as a rule, These00:13:57
substances do not conduct electric current well,00:14:01
and the fifth property is chemical00:14:03
inertness, laziness, inactivity,00:14:08
probably in fact, based00:14:10
on these first three of the00:14:13
four types of crystal lattices, you00:14:15
already understand that properties can be learned by heart it is not00:14:19
necessary to understand the properties that00:14:21
will be characteristic of substances with some kind of00:14:24
crystal lattice, metallic,00:14:26
atomic, ionic, molecular;00:14:28
it is enough to simply recall one00:14:30
bright representative, for example, in the case of a00:14:33
metallic crystal lattice,00:14:35
you can recall the metal and formulate the00:14:37
basic properties from there in order to00:14:39
formulate the00:14:41
properties accordingly substances with an ionic crystal00:14:43
lattice, it is enough to remember00:14:45
some compound With ionic00:14:47
bonds The same table salt00:14:48
sodium chlorine to formulate all these00:14:52
properties We also did not have to00:14:54
include any00:14:57
new neural connections and so on, we00:15:00
just had to Remember everything that00:15:03
we know based on personal experience about00:15:05
such a compound as diamond, that is, there is00:15:07
no need to voice the properties in any case;00:15:10
remember some prominent00:15:12
representative who has this00:15:14
type of crystal lattice and00:15:16
independently deduce for yourself all the00:15:18
necessary properties. Well, the last type of00:15:21
crystal lattice is a molecular00:15:23
crystal lattice, as I think you00:15:25
understand from the name that its nodes00:15:26
contain particles such as molecules.00:15:29
Moreover, they are connected by fairly weak00:15:32
intermolecular interactions, which00:15:35
largely explains their chemical and00:15:37
physical properties. So let’s immediately talk00:15:39
about the properties of these substances, as I already00:15:42
mentioned, molecules in a molecular00:15:45
crystal lattice are connected by very00:15:47
weak interactions, therefore as a00:15:49
rule, these are liquids or gases with very00:15:52
low boiling and00:15:54
melting points that do not conduct00:15:56
electric current in their pure form and00:15:59
are quite weak, let's00:16:02
write this down. So the00:16:04
first one00:16:08
is usually a liquid or gas00:16:13
2 because of these weak intermolecular00:16:16
interactions, it is not quite strong00:16:18
substances the00:16:22
third, respectively, is that they do not00:16:24
conduct electric current in their pure form00:16:28
and the fourth, respectively, is their low00:16:31
boiling and melting points,00:16:32
again low due to these00:16:34
weak bonds, a00:16:41
small caveat Some of them00:16:44
can conduct electricity, for example in00:16:46
solutions or melts But about this we00:16:49
will clearly talk to you about other00:16:51
topics, now we will turn to the most00:16:53
interesting question: how to determine a00:16:56
substance with a molecular crystal00:16:58
lattice; the most important and effective00:17:00
method in this case is everyone’s favorite00:17:03
method of exclusion. That is, if we look00:17:05
at a substance and understand that it does not00:17:07
belong to metal ionic and00:17:10
atomic crystal lattice, then00:17:12
it turns out accordingly. It has00:17:13
the molecular type Kaer, let's prove00:17:17
this with you using the example of carbon dioxide00:17:19
CO2. So CO2 is not a metal,00:17:22
some kind of sodium, chromium, iron00:17:25
is not a metal and therefore does not00:17:27
have a metal crystal00:17:30
lattice, we immediately discard it in CO2 there are00:17:33
no ionic bonds, as a rule, these are00:17:35
bonds between metals and metals, which means they are also ionic in the00:17:38
crystal lattice. It smells exactly the same here00:17:40
and the third moment of this00:17:42
substance is not in our small list00:17:44
for the atomic crystal lattice. Yes,00:17:49
we have there, let me remind you, graphite Diamond,00:17:51
respectively, silicon Boron and so on00:17:54
yes CO2 is in our list no, respectively,00:17:57
CO2 does not belong to the atomic00:18:00
crystal lattice, also if CO2 does not00:18:04
have a metallic and atomic00:18:07
crystal lattice. The only thing that,00:18:09
in principle, the only option left00:18:11
is the molecular Kaer, so by the00:18:14
method of exceptions we have determined with you the00:18:16
type of crystal lattice of CO2 there are00:18:20
also two points to which I would like to00:18:22
draw your special attention. The first is the00:18:25
wonderful word structure, that is,00:18:27
very often they say molecular00:18:29
structure instead of molecular00:18:31
crystal lattice they can say not00:18:34
molecular structure This means that the00:18:36
crystal lattice and smart00:18:38
metallic or, respectively, atomic00:18:40
but not molecular This is the first moment00:18:43
two, the tests may also come across00:18:45
such substances as, for example, fullerene c6000:18:49
white phosphorus p400:18:54
and so on. These substances very much00:18:57
remind us of graphite and diamond and,00:19:01
accordingly, red black phosphorus,00:19:03
which we have in the list with substances00:19:05
having an atomic crystal00:19:08
lattice, but actually00:19:11
these are substances with molecular type of00:19:13
crystal lattice Yes, they are similar But00:19:16
they are not on our list, respectively.00:19:19
Therefore, if they do not have an atomic crystal00:19:22
lattice, they do not have an ionic and00:19:24
metal lattice, only00:19:26
the molecular one remains. Do not forget about our favorite00:19:30
method of exclusion for today,00:19:32
we have all fully discussed such a topic00:19:35
as types of crystal lattices, it will00:19:37
definitely be useful to you in the fourth00:19:38
task of the Unified State Exam. But if you liked00:19:40
this format, do not forget to leave00:19:42
likes under this video, comments in order to00:19:45
actually promote the promotion and00:19:48
release of new videos and be sure to00:19:50
Subscribe to our YouTube channel and00:19:52
turn on the bell so as not to miss00:19:53
further videos With you there was Anastasia00:19:55
Mayer and bye-bye to everyoneDescription:
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The UDL Helper extension is a convenient button that is seamlessly integrated into YouTube, Instagram and OK.ru sites for fast content download.
UDL Client program (for Windows) is the most powerful solution that supports more than 900 websites, social networks and video hosting sites, as well as any video quality that is available in the source.
UDL Lite is a really convenient way to access a website from your mobile device. With its help, you can easily download videos directly to your smartphone.
Which format of "Кристаллические решетки: заучить или понять за 20 минут? | Химия ЕГЭ 2023 | Умскул" video should I choose?
The best quality formats are FullHD (1080p), 2K (1440p), 4K (2160p) and 8K (4320p). The higher the resolution of your screen, the higher the video quality should be. However, there are other factors to consider: download speed, amount of free space, and device performance during playback.
Why does my computer freeze when loading a "Кристаллические решетки: заучить или понять за 20 минут? | Химия ЕГЭ 2023 | Умскул" video?
The browser/computer should not freeze completely! If this happens, please report it with a link to the video. Sometimes videos cannot be downloaded directly in a suitable format, so we have added the ability to convert the file to the desired format. In some cases, this process may actively use computer resources.
How can I download "Кристаллические решетки: заучить или понять за 20 минут? | Химия ЕГЭ 2023 | Умскул" video to my phone?
You can download a video to your smartphone using the website or the PWA application UDL Lite. It is also possible to send a download link via QR code using the UDL Helper extension.
How can I download an audio track (music) to MP3 "Кристаллические решетки: заучить или понять за 20 минут? | Химия ЕГЭ 2023 | Умскул"?
The most convenient way is to use the UDL Client program, which supports converting video to MP3 format. In some cases, MP3 can also be downloaded through the UDL Helper extension.
How can I save a frame from a video "Кристаллические решетки: заучить или понять за 20 минут? | Химия ЕГЭ 2023 | Умскул"?
This feature is available in the UDL Helper extension. Make sure that "Show the video snapshot button" is checked in the settings. A camera icon should appear in the lower right corner of the player to the left of the "Settings" icon. When you click on it, the current frame from the video will be saved to your computer in JPEG format.
What's the price of all this stuff?
It costs nothing. Our services are absolutely free for all users. There are no PRO subscriptions, no restrictions on the number or maximum length of downloaded videos.