8.2.4 An Introduction to Electronegativity

Question 1

An Introduction to Electronegativity

Answer 1

• Electronegativity is a parameter describing the ability of an atom to attract additional electron density to itself.
• Due to decreasing atomic radius, electronegativity increases moving up a group on the periodic table.
• Due to increasing nuclear charge, electronegativity increases moving across a period from left to right

Question 2

note

Answer 2

• By bombarding a series of transition metals with electron beams, Henry G. J. Moseley found that the frequency of the x ray emitted increased with atomic number. He used these results to calculate the atomic numbers of several elements.
• This result can be explained through electronegativity.
  Electronegativity is a parameter describing the ability of an atom to attract additional electron density to itself. Iron has the highest electronegativity of the four elements shown, and therefore the difference in energy between the valence electron and the core electron is greater. This results in the emission of a higher frequency x ray photon when the higher energy electron relaxes to the lower energy orbital.
• Electronegativity combines the concepts of ionization energy, electron affinity, and bond lengths into a single value for each element.
• Linus Pauling developed a scale of the electronegativities of the elements. This scale exhibits periodic trends.
• Moving up a group on the periodic table, the atomic radius decreases. This decreasing radius causes the electrons to feel a higher effective nuclear charge. Therefore, electronegativity increases moving up a group on the periodic table.
• Moving from left to right across a period on the periodic
  table, nuclear charge increases. This increase in nuclear
  charge causes the electrons to be more attracted to the
  nucleus. Therefore, electronegativity increases moving across a period from left to right.

Question 3

On which of the following is the concept of electronegativity not based?

Answer 3

Atomic radius

Question 4

Which of the following periodic trends cannot be directly measured?

Answer 4

Electronegativity

Question 5

The concept of electronegativity was developed by which one of the following scientists?

Answer 5

Pauling

Question 6

Which periodic concepts are summarized by electronegativity?

Answer 6

ionization energy, electron affinity, bond length

Question 7

Which of the following is the least electronegative element and the most electronegative element, respectively?

Answer 7

francium, fluorine

Question 8

What elements have relatively small electronegativity values?

Answer 8

Electropositive elements

Question 9

Which of the following is not directly factored into electronegativity?

Answer 9

number of valence electrons