How are elements on the periodic table primarily organized?

• A. By increasing atomic number
• B. By the number of neutrons in the nucleus
• C. By alphabetical order of element names
• D. By increasing atomic mass

Answer: (A)

Verified step by step guidance

1. Understand that the periodic table is a systematic arrangement of elements based on their atomic structure.
2. Recall that each element is defined by its atomic number, which is the number of protons in its nucleus.
3. Recognize that the periodic table is primarily organized by increasing atomic number, which reflects the number of protons, not neutrons or atomic mass.
4. Note that organizing by atomic number ensures elements with similar chemical properties fall into the same groups or columns.
5. Conclude that the correct organization principle is by increasing atomic number, rather than by number of neutrons, alphabetical order, or atomic mass.