Question

the modern periodic table is arranged from left to right in order of increasing select choice select choice atomic number mass number atomic mass

Explanation:

The modern periodic table is organized based on the atomic number of elements. The atomic number represents the number of protons in an atom's nucleus. This is a fundamental property used for the systematic arrangement of elements. Mass number is the sum of protons and neutrons and varies for isotopes. Atomic mass is the weighted average mass of an element's isotopes. But the key ordering principle in the modern periodic table is atomic number.

Answer:

atomic number