If atom B successfully ionizes atom A, what can you say about the electronegativity of the two atoms?

Electronegativity, symbol χ, measures the tendency of an atom to attract a shared pair of electrons (or electron density).

An atom's electronegativity is affected by both its atomic number and the distance at which its valence electrons reside from the charged nucleus.

The higher the associated electronegativity, the more an atom or a substituent group attracts electrons.