Slides in this set
What is electronegativity?
· A covalent bond is a shared pair of electrons but are these
electrons shared equally between the two bonded atoms?
· The answer is yes if the two atoms are of the same element.
In molecules such as H2 and CL2 the bonding electrons are
· But not if the two bonded atoms are different elements.
One of the bonded atoms has more of a share of the
bonding electrons than the other. This happens if the two
atoms have a different electronegativity.
Electronegativity is the ability to attract the
bonding electrons in a covalent bond…read more
Fluorine is the most electronegative element. Its
electronegative value is 4.0 on the Pauling scale. In
general electronegativity increases from left to right
across the period and as you go up each group.
be measured directly
instead it has to be
calculated. The most
common way is the
scale named after a
scientist who devised it.…read more
In a polar bond, the difference In a covalent bond
in electronegativity between between two atoms
two atoms causes a dipole. A of different
dipole is a difference in electronegativity's
charge between the two the bonding
atoms caused by a shift in electrons are pulled
electron density in the bond. towards the more
atoms. This makes
the bond polar.
The symbol shows
between molecules.…read more
In other words when the bonding pair of
electrons is not shared equally, the bond is a
polar bond. The more electronegative atom
gains a partial negative charge (-). The less
electronegative atom gains a partial positive
e g . polar bond in hydrogen chloride
Chlorine is more
molecule has a
dipole, a pair of
separated charges of
opposite signs.…read more