Chemistry I / Chemical Bonds and Electronegativity
Practice question · Fill in the blanks

Complete the description of how electronegativity varies and what it is not.

Electronegativity ______ from left to right across a period, ______ going down a group, and peaks at ______. It must not be confused with ______, which is measured on a free atom in the gas phase.

Word bank: increases · decreases · fluorine · ionisation energy · caesium

Hints
  1. The trends follow effective nuclear charge, exactly like atomic radius.
  2. One of the bank entries is the LEAST electronegative element, and one is a different property entirely.
Show the answer

Electronegativity increases from left to right across a period, decreases going down a group, and peaks at fluorine. It must not be confused with ionisation energy, which is measured on a free atom in the gas phase.

Why

Electronegativity rises across a period and falls down a group, peaking at fluorine (4.0). Ionisation energy is a different quantity, an energy in kJ/mol measured on an isolated atom, not a tendency within a bond. Caesium is the distractor: it is the least electronegative element.

Read the lesson: Chemical Bonds and Electronegativity →

Practise Chemical Bonds and Electronegativity

The app has 4 more questions on this lesson, and keeps your place in the course. Chemistry I is free to start.

More questions on Chemical Bonds and Electronegativity