Question

The periodic table is called “periodic” because it is arranged to show repeating patterns. What is one of those repeating patterns?

A. atomic mass
B. atomic number
C. number of protons
D. number of valence electrons

Answer 1

The answer is a. Atomic mass

Answer 2

A. atomic mass

Step-by-step explanation:

Periodic Properties of the Elements Mendeleev saw that when the elements were arranged in order of increasing atomic mass, those that had similar properties occurred in a repeating pattern. That is, the pattern was periodic. Periodic means “happening at regular intervals.” Hope this helps!!