D. Changes
Hope this helps :)
Answer is 3
because on the periodic table, the small number above every element is the number of protons
The answer is C. and D. water and aluminum
I think it goes like this.
mass = 78.6 g
molar mass = 60.1 g/mol
amount (in mols) = mass/mol
78.6 g / 60.1 g/mol = 1.30782 mol
^^rounded to 3 sig figs, final answer = 1.31mol