In the periodic table, elements organized by columns share which of the following characteristics?

• A. Identical atomic numbers
• B. Increasing atomic mass from top to bottom
• C. Similar chemical properties
• D. The same number of electron shells

Answer: (C)

Verified step by step guidance

1. Understand that the periodic table is arranged in columns called groups or families.
2. Recognize that elements in the same group have the same number of valence electrons, which largely determines their chemical behavior.
3. Note that elements in the same group do NOT have identical atomic numbers; atomic number increases as you move across periods (rows), not down groups (columns).
4. Observe that atomic mass generally increases from top to bottom within a group, but this is not the defining characteristic of elements in the same column.
5. Conclude that the key shared characteristic of elements in the same column is that they exhibit similar chemical properties due to having the same number of valence electrons.