Why does francium (Fr) have a low electronegativity compared to other elements?

• A. Because it has a high number of protons, which strongly attract bonding electrons.
• B. Because it has a small atomic radius, increasing its ability to attract electrons.
• C. Because it is a transition metal with partially filled d orbitals.
• D. Because its valence electron is far from the nucleus, resulting in weak attraction for bonding electrons.

Answer: (D)

Verified step by step guidance

1. Understand that electronegativity is the ability of an atom to attract bonding electrons towards itself in a chemical bond.
2. Recognize that francium (Fr) is an alkali metal located at the bottom of Group 1 in the periodic table, meaning it has a large atomic radius and its valence electron is far from the nucleus.
3. Recall that as atomic radius increases, the valence electrons are farther from the nucleus and experience more shielding from inner electrons, reducing the effective nuclear attraction on bonding electrons.
4. Note that although francium has many protons, the increased distance and shielding outweigh the nuclear charge, leading to a weaker pull on bonding electrons and thus lower electronegativity.
5. Conclude that francium's low electronegativity is due to its valence electron being far from the nucleus, resulting in weak attraction for bonding electrons, rather than factors like small atomic radius or transition metal characteristics.