What would be the symbol of an atom of tin that has 50 protons and 70 neutrons

How many moles of carbon dioxide will form if 2.5 moles of c3h8 is burned

Ican determine the molar mass of an element by looking on the under the atomic mass for the element. for example the molar mass of phosphorus is 30.974 grams/mole. avogadro’s number tells me the amount of representative particles in 1 mole of any substance. this means 12.011 gram sample of carbon and a 32.0 gram sample of sulfur have the same number of atoms.

What is the subscript for oxygen in its molecular formula