Which planet is most like earth in size and makeup

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 salt water solution,the salt is the blank

Why does a plastic bottle that is sealed at a high altitude change it’s shape when taken to lower altitude