Question

What are the letters on the periodic table called

Answer 1

I’m not sure exactly what you mean by letters, but if you mean abbreviations, those are just the element names. If you mean rows and columns, that question was previously answered.

Answer 2

Periods and Families

Step-by-step explanation:

The horizontal rows of elements are called periods and the vertical columns of elements are called groups/families!

Hope I could help!