How many grams of agno3 are needed to prepare a 0.25 m solution in 500 grams of water?
question 2 options:

125 g

0.125g

21.25 g

170g

How are elements arranged in a periodic table

Nonpoint source pollution is difficult to control because it

The characteristics of two different types of reactions are shown below: reaction a: electrons are gained by the atoms of an element. reaction b: protons are lost by the atom of an element. which statement is true about the atoms of the elements that participate in the two reactions? their identity changes in both reaction a and reaction b. their identity changes in reaction a but not in reaction b. their identity changes in reaction b but not in reaction a. their identity remains the same in both reaction a and reaction b.