Which of the following best explains why elements on the periodic table are arranged in groups and periods?

• A. Elements are grouped by their physical state at room temperature, such as solids, liquids, and gases.
• B. Elements are arranged based on their atomic mass, with heavier elements placed at the top.
• C. Elements are organized according to the order in which they were discovered.
• D. Elements are arranged according to increasing atomic number, which reflects recurring chemical properties and group similarities.

Answer: (D)

Verified step by step guidance

1. Understand that the periodic table is arranged to reflect the properties of elements in a systematic way.
2. Recognize that elements are arranged in order of increasing atomic number, which is the number of protons in an atom's nucleus.
3. Know that this arrangement leads to recurring patterns in chemical properties, known as periodicity.
4. Groups (columns) contain elements with similar chemical properties because they have the same number of valence electrons.
5. Periods (rows) represent elements with increasing atomic number and changing properties across the row.