Which property is generally similar for elements within the same group on the periodic table?

• A. Ionization energy
• B. Atomic radius
• C. Number of valence electrons
• D. Electronegativity

Answer: (C)

Verified step by step guidance

1. Understand that elements in the same group (vertical column) of the periodic table share similar chemical properties because they have the same number of valence electrons.
2. Recall that valence electrons are the outermost electrons involved in chemical bonding and largely determine an element's chemical behavior.
3. Recognize that while properties like ionization energy, atomic radius, and electronegativity can vary within a group due to increasing atomic number and shielding effects, the number of valence electrons remains constant.
4. Therefore, the property that is generally similar for elements within the same group is the number of valence electrons.
5. This similarity explains why elements in the same group often exhibit similar reactivity and form similar types of compounds.