The answer is B. a flashlight uses a battery to operate.
The battery represents the chemical energy. This is converted into electricity, which is converted into light energy.
I believe it to be g/mol of Calcium carbonate
because to finde mass...u must have grams(g) as units....
it is the only one that have g as units
as for the first answer the avogadros number gives u the number of atoms in one mole of calcium carbonate....
the second one is based on ... At s.t.p one mole of gas occupies 22.4 dm³⇒to find volume