3. Chemical Reactions
Points to Remember
♦ A chemical bond is the force of attraction which holds together the atoms in a molecule.
♦ An electrovalent bond is formed as a result of complete transfer of electron(s) from one atom to another.
♦ Atoms which can lose electrons and form positive ions are said to be electropositive.
♦ Atoms which can gain electrons and form negative ions are said to be electronegative.
♦ The total number of electrons lost or gained by an atom to attain the stable configuration of the nearest noble gas is known as the valency of the atom.
♦ The number of electrovalent bonds by an atom can form is called its electrovalency.
♦ Covalent bonds are formed by the mutual sharing of electrons between the combining atoms.
♦ Compounds containing covalent bonds are called covalent compounds.
♦ The. total number of electrons shared by a given atom in the formation of covalent bonds to attain the stable configuration of its nearest noble gas is known as its covalency.
♦ The force that holds the atoms closely together in a metal is known as the metallic bond.