Electronegativity

Question 1

What is electronegativity?

Answer 1

electronegativity is the power of an atom to attract the electron density in a COVALENT BOND towards itself

Question 2

What is electron density?

Answer 2

chemists consider the electrons as charge clouds

the term electron density is often used to describe the way the negative charge is distributed in a molecule

Question 3

What is the Pauling Scale?

Answer 3

used as a measure of electronegativity

it runs from 0 to 4

the greater the number, the more electronegative the atom

Question 4

What does electronegativity depend on?

Answer 4

1) nuclear charge (the larger the nuclear charge - for a given shielding effect - the greater the electronegativity)
2) the distance between the nucleus and the outer shell electrons (the closer the nucleus is to the shared outer main level electrons the greater the EN)
3) the shielding of the nuclear charge by electrons in inner shells

Question 5

What are the trends in electronegativity going up a group in the Periodic Table?

Answer 5

electronegativity increases because the atoms get smaller and there is less shielding by electrons in the inner shells

Question 6

What are the trends in electronegativity going across a period in the Periodic Table?

Answer 6

the electronegativity increases

the nuclear charge increases

the number of inner main levels remain the same

the atoms get smaller

Question 7

Where are the most electronegative atoms found? What are the four most electronegative elements?

Answer 7

at the top right hand corner

ignoring the noble gases which don’t form covalent bonds

the most electronegative atoms are: fluorine, oxygen and nitrogen, followed by chlorine