# 3.28 Sspd_chapter 1_part 11_solid state of matter_crystalline nature  (Page 2/5)

 S.No. Properties Diamond cube(dc) Simple Cube(sc) Body CenteredCube(bcc) Face Centered Cube(fcc) Hexa-gonalClose_pack structure NaCl 1 Vol.of unit cell a^3 a^3 a^3 a^3 (3/2) [√3(ca^2)] a^3 2 No. of atoms percell 8 1 2 4 6 4 cations4 anions 3 No.of atoms per unit vol. 8/ a^3 1/ a^3 2/ a^3 4/ a^3 4/ [√3(ca^2)] 8/a^3 4 No.of nearest neighbours 4 6 8 12 12 5 Nearest neighbourDistance(2r) a√3/4 a/2 a√3/2 a√2/2 a/2 6 Atomic radius a√3/8 a/2 a√3/4 a√2/4 a/2 7 Atomic packingFactor π√3/16=0.34 π/6= 0.52 π√3/8=0.68 π √2/6=0.74 π√2/6=0.74 0.67 8 Examples Ge, Si and Diamond Polonium Sodium,Iron,Chromium Aluminium,Copper,Lead Magnesium,Zinc,Cadmium Ionic solids such as NaCl, AgCl,LiFMgO,CaO

Water shows an anomaly in the range from 4°C to 0°C. With reduction in temperature at and below 4°C the density decreases instead of increasing. At 0°C, the Ice Temperature, it has the lightest density. This is because of the open-pack hexagonal structure of ice crystal. From 4°C to 0°C, the phase transition is occurring through out the volume of liquid and at 0°C the phase transition is complete. At this temperature the whole mass of water is fully transformed into a solid piece of ice. Therefore at 0°C we have the lightest density of Ice. It is this anomaly which helps the survival of fishes in frozen lakes. Nine-tenth of ice-berg is submerged and one-tenth of the ice-berg is visible. Therefore we say that the tip of the ice-berg is visible.

1.11.2 ALLOTROPIC FORMS OF CARBON

There are elements which exist as different crystalline allotropes such as Carbon. This most commonly found element exists as three crystalline allotropes namely Graphite, Diamond and Buckminstefullerene Crystal also known a buckeyball structure. The structure is shown in Figure 1.56 and Figure 1.57 and their properties are tabulated in Table (1.22).

1.11.2.1. DIAMOND CRYSTAL.

In Figure 1.56 we show the Diamond allotropic form of Carbon. As shown in Fig 1.56 A , Diamond is two interpenetrating FCC sub-lattices with one sub-lattice displaced with respect to the other along the diagonal of the cube by a quarter of diagonal length (a√3)/4 where ‘a’ the lattice parameter. Since Diamond unit cell is a cube, its lattice parameter is the side of a cube as shown in Figure 1.56 B. The basic unit cell of Diamond is cube of equal sides ‘a’ length. ‘a’ is the lattice constant of Diamond. Its value is 3.57 Angstrom. The basic unit cell is subdivided into 8 subcubes ABCDEFGH. ABCD comprise the upper 4 subcubes and EFGH comprise the lower 4 subcubes. In the Figure 1.56B , subcube E is hidden due to the perspective view. The subcube A, C, in the upper layer and F,H in the lower layer contain the tetrahedral structure of carbon atoms as shown in Figure 1.56D. As a result the basic UNIT CELL has 8 C atoms at the 8 corners of the cube, 6 C atoms on the six faces of the cube and 4 C atoms in the bodies of A, C , F, H subcube. The net result is that on looking at the PLAN VIEW of Diamond Unit Cell as shown in Figure 1.56C we see one C atom sharing its 4 valence electrons with 4 C atoms at its 4 corners. This kind of structure is repeated through out.

how to know photocatalytic properties of tio2 nanoparticles...what to do now
it is a goid question and i want to know the answer as well
Maciej
Do somebody tell me a best nano engineering book for beginners?
what is fullerene does it is used to make bukky balls
are you nano engineer ?
s.
what is the Synthesis, properties,and applications of carbon nano chemistry
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
so some one know about replacing silicon atom with phosphorous in semiconductors device?
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
for screen printed electrodes ?
SUYASH
What is lattice structure?
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
what's the easiest and fastest way to the synthesize AgNP?
China
Cied
types of nano material
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
what is nano technology
what is system testing?
preparation of nanomaterial
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
what is system testing
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
Hello
Uday
I'm interested in Nanotube
Uday
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
Prasenjit
can nanotechnology change the direction of the face of the world
how did you get the value of 2000N.What calculations are needed to arrive at it
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