How are elements in the periodic table primarily arranged?

• A. By increasing atomic number
• B. By the number of neutrons
• 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 properties.
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 arranged in order of increasing atomic number, not by atomic mass or other criteria.
4. Note that arranging by atomic number ensures elements with similar chemical properties fall into the same groups or columns.
5. Conclude that the correct way elements are arranged in the periodic table is by increasing atomic number.