Describe how changing the particles changed the atom

What’s the percent by mass of carbon in c10h14n2

Tin has ten stable isotopes. the heaviest, 124sn, makes up 5.80% of naturally occuring tin atoms. how many atoms of 124sn are present in 82.0 g of naturally occurring tin? what is the total mass of the 124sn atoms in this sample?

Plz ill give u brainliest which of the following steps is not likely to take place during cellular respiration? a.oxygen combines with carbon of simple sugar. b. energy molecule transfers energy to cells. d. energy is used up.