The fuel used in many disposable lighters is liquid butane, c4h10. butane has a molecular weight of 58.1 grams in one mole. how many carbon atoms are in 3.50 g of butane?

First convert grams to moles using molar mass of butane that is 58.1 g

3.50g C4H10 x (1 mol C4H10)/(58.1g C4H10) = 0.06024 mol C4H10 

Now convert moles to molecules by using Avogadro’s number

0.06024 mol C4H10 x (6.022x10^23 molecules C4H10)/(1 mol C4H10) = 3.627x10^22 molecules C4H10 

And there are 4 carbon atoms in 1 molecule of butane, so use the following ratio: 

3.627 x 10^22 molecules C4H10 x (4 atoms C)/(1 molecule C4H10) 
= 1.45 x 10^23 atoms of carbon are present

answer; i believe that the correct answer is (a) potassium(k)