Which statement best reflects the theme of this paragraph?

What is the formula for calcium iodide

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?

Match the mixture with the substance// i really need on this guys (it’s a pic btw)