what does the first number in the numbering classification system for both wrought and casted aluminum tell…

what does the first number in the numbering classification system for both wrought and casted aluminum tell you?\nthe principal alloying element used or the alloy series\nan alloy modification\nan arbitrary number that identifies a specific alloy in a series
Answer
Brief Explanations:
In the numbering classification system for wrought and casted aluminum, the first number indicates the principal alloying element or the alloy series. For example, 1xxx series is 99% pure aluminum, 2xxx series has copper as the principal alloying element, etc.
Answer:
The principal alloying element used or the alloy series