How is the modern periodic table organized?

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

Answer: (C)

Verified step by step guidance

1. Understand that the modern periodic table is arranged to reflect the properties of elements in a systematic way.
2. Recall that early versions of the periodic table were organized by increasing atomic mass, but this caused inconsistencies in element properties.
3. Recognize that the modern periodic table is organized by increasing atomic number, which is the number of protons in an atom's nucleus.
4. Know that arranging elements by atomic number aligns elements with similar chemical properties into columns called groups or families.
5. Conclude that the correct organization principle of the modern periodic table is by increasing atomic number, not by discovery order, alphabetical order, or atomic mass.