If an atom loses two electrons what charge will it have ?

+2
-1
+1
-2

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?

Chen drew a diagram to compare the ways in which different organisms obtain nitrogen. which label belongs to the area marked z?

The molar mass of nickel(ni) is 58.7 g/mol. how many moles are in an 88 gram sample of nickel?