Electronegativity Flashcards
What is electronegativity
The ability of a nucleus to attract electron density in a covalent bind towards itself
What is electron negativity depends
Nuclear charge
Distance between the nucleus and the outer shell electrons
The shielding of the nuclear charge by inner electrons
I what is special two cases of electronegativity
Smaller the atom the closer the nucleus to the electron density the greater it’s electronegativity
The greater the nuclear charge for the same simulator shielding effect the greater the electronegativity
What is polarity
The unequal sharing of electron between atoms that are bonded together covalently
What is coolant bonds like with atoms with the same polarity
The bond electron density must be shared equally as both atom have the same electronegativity so it’s non polar
What will happens to polarity in two different electronegative atoms
Electrons in the bond will not be shared equally the electron cloud will distort to the atom which is more electronegative so one end is $+ and the other end is $+ so bond is polar
What is a dipole dipole moments
Molecules with polar bonds may have a dipole moment which soles up all the polarity in the bond it can either cancel out or add up leading to a polar molecule
Those with permanent dipoles will attract other molecules with permanent dipoles
What are can see walls forces
The positive and negative charges in an atom or molecules produce weak electrostatic forces between molecules or atoms
How do can set waals forces work
They act between all atoms and molecules and at all times it occurs when the electron density position is changes inducing dipoles in nearby atoms so more electrons the larger the dipole dipole will be
What is hydrogen bonding
Occurs between two electronegative atoms and hydrogen sandwiches between
What features need to be present for hydrogen bonding
An electronegative atom with a lone pair of electrons covalently bonded to a hydrogen atom
How does hydrogen bi sing work
The oxygen atom has a lone pair of electrons in one molecule
In another molecule the oxygen is very electronegative so pulls electron density toward itself leaving a hydrogen which is very positive and has strong electric field as the atom is very small so attracts the lone pair of electrons in the other water molecules towards itself
Represented by dashes
What atoms can hydrogen bonding work with
Oxygen and nitrogen and flourine
Why is hydrogen bonding linear
Pair of electrons in the by covalent bond repels those in the hydrogen and nitrogen
What is special about ice
It’s less dense than water when it freezes the hydrogen bonding holds the molecules in place and slightly less packed so form on top of water rather than beneath
