I need to know number 2 3 4 and 5

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?

Explain what happens at the saturation point when adding salt to water at room temperature.

What is the indicator of the number of ions in solution? the amount of conductivity the amount of precipitate the amount of solute added