Which of the following trends is observed when moving down a group (column) in the periodic table?

• A. Ionization energy increases
• B. Electron affinity becomes more negative
• C. Atomic radius increases
• D. Electronegativity increases

Answer: (C)

Verified step by step guidance

1. Understand the periodic trend concepts: Ionization energy is the energy required to remove an electron from an atom; electron affinity is the energy change when an atom gains an electron; atomic radius is the size of the atom; electronegativity is the tendency of an atom to attract electrons in a bond.
2. Recall that moving down a group in the periodic table means adding electron shells, which increases the distance between the nucleus and the outermost electrons.
3. Recognize that as the number of electron shells increases, the atomic radius increases because the outer electrons are farther from the nucleus and experience more shielding from inner electrons.
4. Know that ionization energy generally decreases down a group because the outer electrons are farther from the nucleus and are held less tightly, making them easier to remove.
5. Understand that electronegativity and electron affinity typically decrease or become less negative down a group due to increased atomic size and shielding, reducing the nucleus's pull on additional electrons.