Research suggests that crochet probably developed most directly from Chinese needlework, a very ancient form of embroidery known in Turkey, India, Persia and North Africa, which reached Europe in the 1700s and was referred to as tambouring, from the French tambour or drum.
POLAR BONDS. 1) Covalent bond between two atoms with unequal electronegativities results in unequal sharing of electrons. 2) Unequal electron sharing leads to partially positive and partially negative charges on opposite ends of the bond.When the two atoms involved in a covalent bond both have equal affinity for electrons, the electrons in the bond are evenly shared between them.hese types of covalent bonds are called polar bonds because the electron distribution or charge is unevenly distributed or polarized. Partial charges are represented by lower case delta (+) Î´+ or lower case delta (-) Î´-. A separation of partial charges within a polar covalent bond is referred to as a dipole.
A polar bond is formed when electrons are unequally shared between two atoms. Polar covalent bonding occurs because one atom has a stronger affinity for electrons than the other (yet not enough to pull the electrons away completely and form an ion). good example of a polar covalent bond is the hydrogen-oxygen bond in the water molecule. Water molecules contain two hydrogen atoms (pictured in red) bonded to one oxygen atom (blue). Oxygen, with six valence electrons, needs two additional electrons to complete its valence shell. Each hydrogen contains one electron.