Question

1. how is the modern periodic table organized?

Explanation:

The modern periodic table is organized based on the atomic number of elements. Elements are arranged in rows (periods) and columns (groups). In periods, elements are ordered by increasing atomic number, and in groups, elements have similar chemical properties due to the same number of valence electrons.

Answer:

The modern periodic table is organized by atomic number, with elements in periods (rows) ordered by increasing atomic number and in groups (columns) having similar chemical properties due to the same number of valence electrons.