Where along a river would the water be clean for swimming or fishing help

What is the number of moles in 15.0 g ash3?

For ai it's atomic number is 13 and it's mass number is 27 how many neutrons does it have

Which of the following compounds would be expected to have the strongest ionic bonds? a)the compound that has b)the largest ions with the greatest charge c)the compound that has d)the largest ions with the least charge the compound that has the smallest ions with the greatest charge the compound that has the smallest ions with the least charge