Chemical Bonding and Molecular Structure

 All of the above given Hybridization : Molecular geometry are correctly matched.

Azo dyes are characterized by the presence of the azo group, which consists of two nitrogen atoms double-bonded to each other (-N=N-).

Carbon has a unique ability to form long chains and rings with other carbon atoms, a property known as catenation. This allows it to form a vast number of organic compounds.

A molecule is the smallest unit of a chemical compound that retains the chemical properties of that compound.

Ionic compounds have a high density. They are generally heavier than water. The oppositely charged ions in an ionic compound are held very closely by strong electrostatic forces of attraction, resulting in the number of ions per unit volume increases. Consequently, increasing in mass per unit volume of the compound.

Size of the cation involved in bonding is smaller compared to the neutral atom. A cation loses electrons, so there is a reduction in the number of shells. Hence, the size of the ion becomes smaller.

The covalent bonding occurs when two (or more) elements share electrons. Covalent bonding occurs because the atoms in the compound have a similar tendency for electrons (generally to gain electrons). The ionic bonding is a one in which a complete transfer of electrons takes place between the atoms.

Due to non-directional nature of the polar bonds present in these compounds they do not exhibit isomerism.

A magnesium atom needs to lose two electrons, whereas the nitrogen atom needs to gain three electrons to attain the octet.The chemical formula for magnesium nitride is Mg₃N_2. Two magnesium atoms donate two electrons to each nitrogen atom while one magnesium atom donates one electron to each of the nitrogen atom. Hence, an ionic bond is formed. Magnesium and nitrogen, thus, attain stability by gaining the octet state.

A molecule of oxygen contains two oxygen atoms joined by a double covalent bond.Thus, the two atoms of oxygen share two electrons each and do not require any more electrons because they have already attained stable octet configurations. If an atom of oxygen having six electrons comes closer to the oxygen molecule, the new atom may share a lone pair of electrons from either of these two oxygen atoms, which donates to the third oxygen atom without sharing any of the electrons of the third oxygen atom. As a result, a coordinate bond is formed between one of the oxygen atoms of the oxygen molecule, and the third atom of oxygen.

All of the above factors favours the formayion of  covalent bonds.

Ionic compounds have high melting and boiling points. For example, sodium chloride has a high melting point of 1472 ^oF and boiling point of 2575.4 ^oF. Lithium chloride has a melting point of 1122.8 ^oF and boiling point of 2462 ^oF. Potassium chloride has a melting point of 1526 ^oF and boiling point of 2732 ^oF. As these compounds contain ions held together by strong electrostatic forces, very high amount of energy is required to overcome this force and break the crystal lattice. This explains the high melting point and boiling point of ionic compounds.

It is a special type of a covalent bond wherein the shared pair of electrons is supplied by only one of the bonding atoms. A lone pair of electrons is present in one of the atoms.e.g.Hydronium ion [H3O⁺ ] It is formed by the combination of water molecule and hydrogen ion. The oxygen atom in a water molecule has two lone pairs of electrons. It donates one pair to the hydrogen ion. Oxygen is thus the donor and hydrogen ion, the acceptor. The hydrogen ion carries over its charge to the hydronium ion.

Ionic compounds are hard crystalline solids. The crystal of sodium chloride has a definite shape. There is a strong electrostatic force of attraction, which holds the ions together. The ions cannot be easily separated. The crystals are hard and brittle.

The hydrogen bond is really a special case of dipole forces. A hydrogen bond is the attractive force between the hydrogen attached to an electronegative atom of one molecule and an electronegative atom of a different molecule. Usually the electronegative atom is oxygen, nitrogen, or fluorine, which has a partial negative charge. The hydrogen then has the partial positive charge.