Question

the energy required to remove electrons is the definition of: atomic number, electronegativity, atomic radius, ionization

Explanation:

• Atomic Number: The number of protons in an atom's nucleus, not related to electron removal energy.
• Electronegativity: A measure of an atom's ability to attract electrons, not about removing electrons.
• Atomic Radius: The size of an atom, unrelated to electron removal energy.
• Ionization (specifically Ionization Energy): Defined as the energy required to remove an electron from an atom or ion.

Answer:

D. Ionization