Which term is used to refer to the columns of the periodic table of elements?

• A. Blocks
• B. Periods
• C. Groups
• D. Families

Answer: (C)

Verified step by step guidance

1. Understand that the periodic table is organized both horizontally and vertically to classify elements based on their properties.
2. Recognize that the horizontal rows in the periodic table are called 'Periods', which represent elements with increasing atomic numbers.
3. Know that the vertical columns in the periodic table are called 'Groups' or 'Families', which contain elements with similar chemical properties.
4. Note that 'Blocks' refer to sections of the periodic table based on electron configurations (s, p, d, f blocks), not columns.
5. Therefore, the term used to refer to the columns of the periodic table is 'Groups' or 'Families'.