Its All about Pj Problem Strings (SiPjAjk) - 7 Spaces Of Interest (Si) and their associated Basic Sequences; 7 Pj Problems of Interest (PPI) and their Alleles (Ajk)
(1) The general representative string for the structure of matter and the implicit string that establishes the structure were indicated in a previous problem. Here, we examine specific concepts associated with the covalent bonding that establishes molecular shapes.
(a) Will a substance with electronegativity of 3.0 covalently bond with another substance with electronegativity of 0.9? Represent this bonding with strings
(b) Will a substance with electronegativity of 2.1 covalently bond with a substance with electronegativity of 3.0? Represent this bonding with strings.
(c) What is the nature of the covalent bonding between two substances with the same electronegativity.
(d) What is the difference between a polar molecule and a dipole.
(e) Define bond length and bond angle. Write representative strings for each.
1(a) The electronegativity of an atom in a covalent bond is a measure of its ability to draw bonding electrons to itself. In a covalent bond, the electrons shared are closer to the atom with the higher electronegativity. Chlorine (Cl) has electronegativity of 3.0. Sodium (Na) has electronegativity of 0.9. The absolute difference in electronegativity is significantly high so as to cause a complete transfer of electron to chlorine. Consequently an ionic bond is formed. A covalent bond is not formed.
(S7P3A31)chlorine >> (very much greater) (S7P3A31)sodium
1(b) Hydrogen has electronegativity of 2.1. Chlorine has electronegativity of 3.0. The absolute electronegativity difference is not large enough to cause a complete transfer of electrons. So a covalent bond is formed. However, the shared electrons are closer to the chlorine atom. In general, sharing of electrons will occur if the absolute difference in electronegativity is less than 1.7. The atom with the higher electronnegativity will draw the shared electrons closer to itself. The electrons are equally shared between atoms with the same electronegativity (i.e difference is zero).
(S7P3A31)chlorine > (S7P3A31)hydrogen
1(c) The shared electrons are equally shared.
1(d) A polar molecule is a dipole. A polar molecule is formed when the bonding electrons spend more time near one atom than the other usually as a result of difference in electronegativity. Consequently, there is a partially positive charge region and partially negative charge region in the molecule.
Bond length is the normal distance between the nuclei of bonding atoms. Representative string is
Bond angle is the angle formed by two bond axes (bond axis is the line connecting the nuclei of two bonded atoms) extending from the same atom.
An angle in radians is a ratio of arc length and radius length. So its representative string is
(S7P1A12)arc length/(S7P1A12)radius length. The center of the circle is the nuclei of the atom from which the bond axes extend.
Specific molecular shapes are established by bond lengths and bond angles.