Consider the symbol subscript b superscript a baseline upper x where x stands for the chemical symbol for an element. what information is given by a and b?

Explanation:

According to the periodic table chart, symbol of an element resides at the center of each box.

And, a number at the bottom of each symbol represents the atomic number of the respective element.

Whereas a number at the top of each symbol represents the atomic mass of the respective element.

For example, sodium is represented as in the periodic table. Hence, atomic number of sodium is 11 and its atomic mass is 23 g/mol.

Thus, we can conclude that subscript "b" shows atomic number and superscript "a" shows atomic mass.