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

• A. By increasing atomic number, with elements arranged in periods and groups based on similar chemical properties
• B. By increasing atomic mass, with elements grouped by their physical state at room temperature
• C. By decreasing atomic radius, with noble gases placed at the top
• D. By alphabetical order of element names, with metals on the left and nonmetals on the right

Answer: (A)

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 primary organizing principle of the periodic table is the atomic number, which is the number of protons in an atom's nucleus.
3. Recognize that elements are arranged in rows called periods, where each period corresponds to the filling of a principal electron shell.
4. Identify that elements in the same column, called groups or families, share similar chemical properties due to having the same number of valence electrons.
5. Conclude that the periodic table is organized by increasing atomic number, with elements arranged in periods and groups based on similar chemical properties.