Question

18
which property of elements increases down a group but decreases across a period? *
(0.5 points)
ionization energy
electronegativity
atomic radius
ionic radius

Explanation:

• Ionization energy: Increases across a period (due to increased nuclear charge attracting electrons more strongly) and decreases down a group (as electrons are in higher - energy shells, farther from the nucleus).
• Electronegativity: Increases across a period (more tendency to attract electrons) and generally decreases down a group (electrons are less tightly held).
• Atomic radius: Decreases across a period (as protons pull electrons in more tightly) and increases down a group (new electron shells are added).
• Ionic radius: Trends are more complex depending on ion type (cation/anion), but overall not the property with the described simple trend.

Answer:

Atomic radius