Atomic and Molecular
structure
An atom is made up of protons, neutrons and electrons.
Protons are positively charged and they denote the
atomic number. Neutrons have no electrical charge.
Protons and neutrons are present in the nucleus.
Electrons are negatively charged and present in the
orbits surrounding the nucleus. Valence electrons are
the number of electrons in the outer shell. Organic
acids are those that are derived from living organisms,
usually from metabolism. Esters are condensation
products of carboxylic acids with the removal of water.
. Isotopes have same number of protons but different
number of neutrons. Loss or gain of electrons is seen in
ions. Radicals have a single electron; there is no loss
or gain of electrons in them. . Lewis structures are
drawn using the valence electron. Each pair of electrons
makes one bond.
Types of carbon molecules
Carbon molecules are of four types: Stable neutral molecule,
carbanion, carbocation and radical. A stable neutral molecule has
not gained or lost electrons, carbanion has gained electrons,
carbocation has lost electrons and radical is neutral and has a
single electron.
Stereospecificity
Stereoisomers have the same atomic formula and connectivity but
differ in the 3D position of the atoms. Chiral carbon has four
different groups attached.
Intramolecular bond interactions
Electronegativity is an atom�s ability to attract electrons. Bond
polarity occurs when the bonding electrons are not shared equally in
a covalent bond. There are mainly two types of bonding, ionic and
covalent. In ionic bonding, transfer of electrons takes place. In
covalent bonding, sharing of electrons occurs. It may be either
polar covalent bonding or non polar covalent bonding. Bond cleavage
is of two types: hemolytic- each fragment gets one electron,
radicals are formed. Heterolytic � one fragment gets both electrons
and the other fragment gets no electrons, ions are formed.
Intermolecular forces
Intermolecular forces are of three types: London dispersion forces �
between non polar molecules, dipole-dipole forces between polar
molecules, hydrogen bonding between molecules with OH, -NH or HF.
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