what is Ionic Bond????( all the details)?

Answer 1

Ionic bonds are formed through the electrostatic attraction between two oppositely charged ions. This type of bond normally occurs between metallic and non-metallic elements. Metals typically have few valency electrons, and occur in groups I, II, and III of the periodic table; reactive non-metals typically have more electrons in their outermost shells, and occur in groups IV, V, VI, and VII. An ionic bond occurs when a metal loses all its valency electrons, leaving a positively charged ion with a noble gas structure, and a non-metal gains the number of electrons it requires to give it a noble gas structure, and becomes a negative ion. A sodium atom, for example, has the electronic structure of 2.8.1; when it loses an electron, it becomes a positively charged sodium ion, Na+, with the electronic structure of neon, 2.8. A chlorine atom has the structure 2.8.7; when it gains an electron, it becomes a negatively charged ion Cl-, with the electronic structure of argon, 2.8.8. Similarly, a calcium atom (2.8.8.2) loses two electrons to become a Ca2+ ion, while an oxygen atom (2.6) gains two electrons to become an O2- ion, and so on.

The ionic bond occurs by means of the attraction between these charged particles, but because there are, of course, millions and millions of them in any given sample of sodium chloride, they do not just pair off to make simple “molecules”. Instead, the positive ions cluster as close as they can round the negative ions, and similarly the negative ions cluster round the positive ions. The net result of this process is that a regular lattice of ions is formed, whose structure, and hence the shape of the resulting ionic crystal, depends on the sizes of the ions and their relative charges. There must, in the end, be an equal number of ions of each charge to ensure that the final structure is neutral, so it is justifiable to write the formula, NaCl, for example, for an ionic compound. However, it must be noted that there is no such entity as a single molecule of an ionic compound, in the way that there can be a single molecule of a covalent compound. A useful way to represent a compound formed by an ionic bond is to show the charges on the ions, Na+Cl-.

Lattice energies, the equivalent of bond energies for covalent compounds, are of the order of 600 to 1,000 kJ/mole, for compounds containing singly charged ions, and higher if either or both of the ions has a multiple charge.

A. Properties


Ionic Compound






Ionic Compound
The ionic bond is a form of chemical linking of atoms in which electrons are transferred from one atom to another so that both end up with completely filled electron shells. In the case of potassium chloride, each potassium atom loses a single electron, which is gained by a chlorine atom. When the electrons, which have a negative electrical charge, have been transferred, the atoms they have left become positively charged ions, while those to which they are added become negatively charged ions. Positive and negative ions strongly attract each other, and they finally position themselves in a regular lattice in which each ion’s immediate neighbours are of the opposite kind.
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Typically, compounds containing ionic bonds are crystalline solids. This is because the arrangement of the ions is dictated by their sizes and charges. Every ion is strongly bonded to its neighbours, and the whole is thus held in a rigid lattice with a specific shape.

They have high melting and boiling points. This is because the very strong bonding associated with ionic compounds means that much energy is required to break these bonds.


Salt Crystals






Salt Crystals
This scanning electron micrograph shows pure salt, or sodium chloride, that has been recrystallized from distilled water. The crystal is built up from a cubic lattice of sodium and chloride ions.
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They are soluble in water. This is because water is a so-called ionizing solvent, because of its polar nature. The water molecule is capable of attaching itself to both positive and negative ions, because the negative end of the water molecule is attracted to the positive ions, and the positive end of the water molecule is attracted to the negative ions. The liquid water is therefore capable of carrying away the ions into solution (in the form of "hydrated" ions), so that the solid eventually dissolves. Non-polar solvents do not dissolve ionic solids.

Compounds containing ionic bonds also conduct electricity when in solution (water) or when molten. This is because both the solution and the molten compound contain ions that can move about when an electric current is passed through. Solid ionic compound cannot conduct electricity as the ions are held in their rigid lattice, and are not free to move.

IV. COORDINATE OR DATIVE COVALENT BOND

In a normal covalent bond, each one of a shared pair of electrons comes from a different atom. Sometimes, however, both electrons of a shared pair come from the same atom. Such a bond is called a coordinate, or dative covalent, bond.

Aluminium is in group III of the periodic table, and has three electrons in its outermost shell. Even when it uses these electrons in normal covalent bond formation, for example with chlorine to form aluminium chloride (AlCl3), it still does not achieve the eight electrons to give it a noble gas structure, and the six it has leaves space for two more. If aluminium chloride vapour is allowed to mix with ammonia gas (NH3), they react rapidly to form a compound with the formula NH3.AlCl3. The lone pair of electrons in the ammonia molecule (the "donor" molecule) is used to complete the octet of electrons round the aluminium atom in the aluminium chloride molecule (the "acceptor" molecule), and this is called a coordinate bond. It can be represented in normal text by an arrow going from the donor molecule to the acceptor, for example, NH3→AlCl3. This type of bond occurs in ions such as NH4+ and H3O+, and many organic and inorganic molecules. Once a coordinate bond has formed, it is indistinguishable from a normal covalent bond; the difference lies solely in the way in which it was formed. Compounds containing these bonds therefore have similar properties to those containing covalent bonds.

V. METALLIC BOND

This is the bond which occurs within metal structures (see Metals). A simple explanation of the bonding in metals is that they consist of ionized atoms in which the free electrons form a homogeneous "sea" of negative charge. The electrostatic attraction between the positive metal ions and the sea of electrons is responsible for the bonds between the metal atoms.

A. Properties

Metals are normally crystalline solids, although we normally only see this with careful examination under the right circumstances. This is a consequence of the lattice of metallic ions having a specific shape for each different metal.

The strength of the metallic bond gives most metals high melting and boiling points. Metals are insoluble in water because they are incapable of bonding chemically with it. They also conduct electricity well because the sea of delocalized electrons, in which the ionic lattice is embedded, can move when a potential difference is applied to the metal.

VI. HYDROGEN BOND


Water Molecule






Water Molecule
A water molecule consists of an oxygen atom and two hydrogen atoms, which are attached at an angle of 105°. Each hydrogen atom possesses a pair of electrons that are not involved in bonding to the oxygen atom. These electrons form a region of negative electric charge, making the whole molecule electrically polarized. This polar quality accounts for the strong bonding between molecules and for the unusual properties of water, such as the fact that it expands as it freezes.
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Hydrogen is unique among the elements in that when it is covalently bonded to another atom all its electrons are in use in bonding (it only has one!). Therefore, its nucleus is not shielded by an inner shell, or shells, of electrons, as in the case of all other elements. If hydrogen is combined with one of the very electronegative elements, such as oxygen, in water, the bonding pair of electrons is pulled strongly towards the oxygen atom, leaving the hydrogen atoms strongly positive. Because the water molecule is not straight (see above), the hydrogen end of it is positively charged, and the oxygen end is negatively charged, that is it is a polar molecule. There is therefore a strong attraction between different molecules of water, and this has a marked effect on its properties, in particular because more energy is required to separate the molecules from each other than would otherwise be the case. This gives water a much higher boiling point than would be predicted by other considerations, such as its molecular mass. Indeed, water would be a gas without hydrogen bonding, with dire effects for life as we know it.

Hydrogen bonds typically have a bond energy of the order of between 10 and 50 kJ/mole; they are present in the structures of proteins, carbohydrates, and nucleic acids, and are therefore very significant in many biological processes.

VII. VAN DER WAALS FORCES

Van der Waals Forces are the weakest of the bonds that occur between molecules, having a bond energy up to about 5 kJ/mole (see Van der Waals Forces). Van der Waals forces exist because, although all molecules are electrically neutral overall, at any instant the electron cloud surrounding the positive nuclei is not symmetrically distributed, so that there is a little more of it to one side of the molecule than the other. This gives rise to a small dipole in each molecule at any instant, and these small dipoles attract one another.

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Answer 2

Directory > Reference > Britannica Concise ionic bond
Electrostatic attraction between oppositely charged ions in a chemical compound. Such a bond forms when one or more electrons are transferred from one neutral atom (typically a metal,

Answer 3

Hay.. in detail means it's not a good question here...
u can search in the Net u'll find Lot of websites..
If u have question then it's better....anyway..
The Bond forms due to electrostatis interaction of protons and electrons .. between atoms and net result is Bond

Answer 4

it is a type of strong bond formed by electrostatic attraction between ions. Usually occurring betwwen metals and non metals. Table salt, NaCl is an example.

Answer 5

see...+ve always attracts -ve... so when a +velyu charged atom comes close to -vely charged one (they must have only a little charge one- two units only) the coulombs forces keep them in that state thus froming an ionic bond

for more details try searchin on gooogle or ask

Answer 6

this might will serve u well
http://www.answers.com/ionic%20bond

Answer 7

look in this site....

http://en.wikipedia.org/wiki/Ionic_bond

best answer?