What human activity is the major cause of acid rain

You are making a solution of calcium chloride dissolved in water. you add solid, stir, and it dissolves. you add just a spatula tip full, stir, and the solid does not dissolve. how could you describe the solutions before and after adding the spatula tip amount

In the reaction between a crushed antacid tablet and vinegar what gas is emitted

What will most likely happen when two bromine atoms bond together?