Which of the following best describes how the periodic table of the elements is organized?

• A. By alphabetical order of element names, with metals and nonmetals separated
• B. By decreasing atomic radius, with elements arranged randomly
• C. By increasing atomic mass, with elements grouped according to their physical state at room temperature
• D. By increasing atomic number, with elements arranged in periods and groups based on similar chemical properties

Answer: (D)

Verified step by step guidance

1. Understand that the periodic table is a systematic arrangement of elements based on their atomic structure and properties.
2. Recall that the key organizing principle of the periodic table is the atomic number, which is the number of protons in an element's nucleus.
3. Recognize that elements are arranged in order of increasing atomic number from left to right and top to bottom.
4. Know that elements are grouped into periods (rows) and groups (columns) where elements in the same group share similar chemical properties due to having the same number of valence electrons.
5. Conclude that the periodic table is not organized alphabetically, by atomic mass, or randomly, but by increasing atomic number with elements grouped by similar chemical behavior.