Download Structural formula

Structural
Formula
Done by: Dhabya Mohammed
STRUCTURAL
FORMULAS
The structural formula represents the arrangements of
atoms in a way that a chemical equation cannot. One
of the advantages of structural formulas is their
ability to describe the structure of an "isomer". A
simple example of this can be observed in one of the
hydrocarbons, butane, C₄H₁₀
LEWIS STRUCTURES (OR "LEWIS DOT
STRUCTURES") ARE FLAT GRAPHICAL FORMULAS
THAT SHOW ATOM CONNECTIVITY AND LONE PAIR
OR UNPAIREDELECTRONS, BUT NOT THREEDIMENSIONAL STRUCTURE. THIS NOTATION IS
MOSTLY USED FOR SMALL MOLECULES. EACH LINE
REPRESENTS THE TWO ELECTRONS OF A SINGLE
BOND. TWO OR THREE PARALLEL LINES BETWEEN
PAIRS OF ATOMS REPRESENT DOUBLE OR TRIPLE
BONDS, RESPECTIVELY. ALTERNATIVELY, PAIRS OF
DOTS MAY BE USED TO REPRESENT BONDING
PAIRS. IN ADDITION, ALL NON-BONDED ELECTRONS
(PAIRED OR UNPAIRED) AND ANY FORMAL CHARGES
ON ATOMS ARE INDICATED.
LEWIS
STRUCTURES
Molecular formulas describe the exact number and type of atoms in a
single molecule of a compound.
The constituent elements are represented by their chemical symbols,
and the number of atoms of each element present in each molecule is
shown as a subscript following that element’s symbol.
The molecular formula expresses information about the proportions
of atoms that constitute a particular chemical compound, using a single
line of chemical element symbols and numbers. Sometimes it also
includes other symbols, such as parentheses, dashes, brackets, and plus
(+) and minus (–) signs.
Molecular formula
Space filling
model
A SPACE-FILLING MODEL, ALSO KNOWN
AS A CALOTTE MODEL, IS A TYPE OF
THREE-DIMENSIONAL (3D) MOLECULAR
MODEL WHERE THE ATOMS ARE
REPRESENTED BY SPHERES WHOSE RADII
ARE PROPORTIONAL TO THE RADII OF THE
ATOMS AND WHOSE CENTER-TO-CENTER
DISTANCES ARE PROPORTIONAL TO THE
DISTANCES BETWEEN THE ATOMIC
NUCLEI, ALL IN THE SAME SCALE. ATOMS
OF DIFFERENT CHEMICAL ELEMENTS ARE
USUALLY REPRESENTED BY SPHERES OF
DIFFERENT COLORS.
the ball-and-stick model is a molecular model of a chemical
substancewhich is to display both the three-dimensionalposition
of the atoms and the bonds between them.
The atoms are typically represented by spheres, connected by
rods which represent the bonds. Double and triple bonds are
usually represented by two or three curved rods, respectively, or
alternately by correctly positioned sticks for the sigma and pi
bonds.
In a good model, the angles between the rods should be the same
as the angles between the bonds, and the distances between the
centers of the spheres should be proportional to the distances
between the corresponding atomic nuclei. The chemical element
of each atom is often indicated by the sphere's color.
BALL AND STICK MODEL
THANK YOU FOR
WATCHING