No Lead bonding and simple ionic bond

Atoms are arranged as close as possible in solid form to form a single substance in the form of metal or rare earth elements. Numbers of bonds per unit volume at a maximum while the bond energy per unit volume to a minimum. Crystal structure formed is a form of geometry in the space where the atoms are considered as rigid balls have same size. The maximum number of atoms, which can be arranged deskilling one atom in contact with all atoms, is 12. There are two forms of the composition of the hexagonal arrangement of the meeting (HCP) and cubic arrangement of the meeting (CCP) or face centered cube (FCC). Most metals that do not have the structure of the metal composition of the meeting is to outsmart (NA, K, etc.), and transition metals (Fe, Cr, W, etc.). All that body centered cubic structure have (BCC), the density structure in BCC is lower than the density of the HCP and FCC.

Rock salt crystal structure
Major anions arranged in the form of a cube and all place intersisil of 6 fold coordination filled by cations. A large number of compounds have a structure such that, for example MgO, CaO, MnO, TiC, ZrN, etc.

The structure of cesium chloride
In the structure of CsCl, CsBr, and Csl, the atoms occupy a place in the middle of the cube form the BCC structure formed by atoms of isomers. Cations and anions in the coordination of the two orders of magnitude 8.

Structure wurtzit
This structure has a hexagonal arrangement of the anion, and half of interstitial tertahedral filled by small cations. Compounds having this structure is a parrot, Zn), AIN, GaN, Inn, etc.

Zinc alloy structure and blen
Another structure that has the structure of zinc coordination tetrahedral blen. In this structure half of the cube arrangement interstitial tetrahedral meeting of anions in the contents of the small cations. Compounds II-IV include SnSe, ZnTe, CdS, CdSe, CdTe, and compound III-IV, including the AIP, AlSb, GaP, GaAs, GaSb, LNP, LnSb, BN cube and so on.

Rutile structure
Rutile (TiO2) has a unit structure slightly distorted from TiO6 octahedron formed by six oxygen ions, the center is occupied by Ti4 +. Cations fill the octahedral site is only partially available. This structure is owned by GeO2, PbO2, SrO2, MnO2, NbO2, TeO2, TiO2, VO2, WO2 and some other oxides, as well ZrF2, MgF2, CoF2 and other fluoride Kristal.

Ilmenite structure, alpha-aluminia
In this structure, oxygen ions are arranged in a hexagonal arrangement of meetings, and SL3 + ions filling two-thirds of the coordinated folding 6 in the layer arrangement of the meeting. This structure is a special structure where most octahedron AlO6 provide field-field. Compounds that have a structure are Cr2O3, Co2O3, Ti2O3, V2O3, Rh2O3, etc. Further compounds which have two kinds of cation Al3 + ions occupy the place in question the structure of alpha-alumina, namely ABO3 structure (A and B are different elements), called srtuktur ilmenite. Compounds that have the structure of this ilmenite are FeTiO3, MgTiO3, MnTiO3, CoTiO3, NiTiO3, etc.
Spinel structure
Snipel structural arrangement of atoms in a cubic arrangement of oxygen meeting. One-eighth of the tetrahedral arrangement of layers formed in the meeting of the O2-filled ion by divalent cations and half of the octahedral cations filled by trivalensi. One unit cell contains eight chemical units of the atoms. Chemical formulas of compounds that have a spinel structure represented by AB2O4 where:
A fill-ion and ion B tetrahedral  fill the octahedral or
-Half of the ion B filling the tetrahedral fill, the remaining ions A and B ions filling the octahedral.

Perovskite structure
The structure of the uttered above is based only on meeting arrangement of oxygen ions. But in the perovskite structure, partly berpastisipasi cations in the structure of the composition of the meeting. In perovskite, ion and O2 + O2-cube structure to form the composition of the meeting, and a small, Ti4 + ions are highly charged oktohedral occupy interstitial places.

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Metallic bond and Bond dipole

Metallic bond

In explaining the metallic bond in need of a thorough description of the electron's energy levels through quantum mechanics. Intuitively and easy to understand, Drude loorentz at the beginning of the 20th century proposed a model. With these models one can explain many things about the nature of nature, and can also explain the metallic bond as the first approach. This model explains that some outer electrons away from atoms form a cloud of electrons scattered throughout the crystal.

A metal can be said as a material composed of cations submerged in a cloud of electrons, and the attractive forces between the cation and the electron cloud is a bond of cohesion. In a metal crystal there is no limiting factor, for example, the amount and direction of covalent bonds in the crystal bonding and electrical neutrality in the crystal ions. Many metals have a crystalline arrangement of two kinds of arrangement of meetings, where the atoms are arranged at the meeting. This gives an explanation why the metals have high densities and have the properties of clay as well as easy on the wrought. Electrical conductivity and good heat on metals can be understood from the easy movement of electrons.

Bond dipole

Ties are much weaker than the other three types of bonding (ionic, metallic and covalent) is the bond dipole, which is the bond that caused the electrostatic attractive forces of molecular dipoles or group of atoms. Molecule formed by covalent bonds often form a permanent dipole because the electrons are in the middle between bonded atoms, and a positive charge and negative charge is not evenly distributed. Molecules attract each other electro statically between the positive and negative ends resulting in a bond. Bond dipole of the hydrogen atom as a positive end-called hydrogen bonds are quite strong bond because the small radius of the hydrogen ion. Association also has a permanent dipole nature of lead.

There is also a bond is called bond dipoles that do not have a fluctuating nature of lead. This happens because at any moment there are more electrons on one side of the nucleus than in the other. This bond on the bond called van der Walls, a weaker binding one level of the hydrogen bonding.

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General Definitions Crystal

All metals, most ceramics and some polymers form crystals when the material is frozen. By this we mean that the atoms arrange themselves regularly and repeatedly in three-dimensional pattern. This kind of structure called a crystal.

Regular pattern in the long run involving tens of atomic distances generated by the coordination of atoms in the material. Besides, this pattern is sometimes also determines the outer shape of the crystals, examples of which can be expressed are six stars form snowflakes. Flat surfaces of rocks precious stones, crystal quartz (SiO 2) even ordinary table salt (NaCl) is the outward appearance of the arrangement in the crystal itself. In every instance that was pointed out, the atomic arrangement in the crystals exist even at the outer surface shape change. Crystallographic structures of quartz in the outer surface do not change even though it rubbed so as to form rounded grains of sand beaches round. The same thing we encountered on the hexagonal arrangement of water molecules in ice or frost.

Unit cell, Tata length range that is characteristic of crystals. This model shows some atomic lattice pattern that can occur when there is one kind of atom. Because the pattern of atoms is repeated ad infinitum, to further ease the crystal lattice is divided in the unit cell. This unit cell has a finite volume; each has features in common with the crystal as a whole.

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The concept of the Association of Atomic

Ikatan Primer

• Ionic
• Kovalen
• Metallic/logam

Ionic Bond (Ikatan Ion)
An ionic bond is created between two unlike atoms with different electronegativities, or Strong Coulomb interaction among negative atoms (have an extra electron each) and positive atoms (lost an electron).e.g. NaCl. When sodium donates its valence electron to chlorine, each becomes an ion; attraction occurs, and the ionic bond is formed

Covalent Bond (Ikatan Kovalen)
Electrons are shared between the molecules to saturate the valency, e.g. H2, Cl2

Metallic Bonds (Ikatan Logam)
The metallic bond forms when atoms give up their valence electrons, which then form an electron sea.  The positively charged atom cores are bonded by mutual attraction to the negatively charged electrons

Ikatan Sekunder :

There is no electron transfer (van der Waals forces) occurred due to the interaction between elements of the charged

Interactions are formed as a result of polarization of molecules or groups of atoms.  In water, electrons in the oxygen tend to concentrate away from the hydrogen.  The resulting charge difference permits the molecule to be weakly bonded to other water molecules

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STRUCTURE OF ATOM - Is it an atom?

ATOM = (protons + neutrons) + Electron

Atomic number = number of protons = number of neutrons in an atom 

Atomic mass number (mass) = mass of the neutron proton + 


Mass of proton = mass of neutron = 1.67 x10 -27 kg 
Electron mass = 9.11 X 10-31 kg 


The atomic mass unit (amu) as the unit of atomic weights, as is standard 


1 / 12 heavy atoms 12C = 1.66 x 10 -24 g = 1 amu 
The atomic weight is often expressed per mole (g / mol) 


One mole stating the number of particles that have mass in grams. 
The number of atoms in one mole is given by Avogadro's number, N = 6.023 x 1023

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