Which is the basis of the modern periodic table?

The correct answer is Atomic Number.

Key Points 

• In the Modern Periodic Table, the arrangement of elements is based on their increasing atomic number in the horizontal rows.
• The Modern Periodic Table is used to predict the properties of elements.

Important Points 

• Elements in the modern periodic table are arranged in 7 periods and 18 groups.
• Horizontal rows are called periods and vertical columns are called groups.
• According to their shared physical and chemical properties, the elements can be grouped into the major categories of metals, metalloids, and nonmetals.