This must be a universal indicator, the pH is going down everytime you add more :)
Never mind, I did the problem wrong, I deeply apologize.
Molar mass Li2CO3 = 73.89 g/mol
Molar mass Li = 6.94g/mol Li = 6.94*2 = 13.88g
% LI = 13.88/73.89*100 = 18.78% perfectly correct.
It’s D. Rutherford discovered the atomic nucleus.
