(A) if both sentences are true, (B) if both sentences are false, (C) if the first sentence is true but the second is false, and (D) if the first sentence is false but the second is true. 1. From the air, oxygen can slowly diffuse across the water’s surface from the surrounding atmosphere, or be mixed in quickly through aeration, whether natural or man-made. The aeration of water can be caused by wind (creating waves), rapids, waterfalls, ground water discharge or other forms of running water. 2. Nuclear energy is synonymous to atomic energy. Uranium is often used as fuel in nuclear reactors because its atoms do not split apart easily. 3. In collecting the tap water sample used in the experiment on dissolved oxygen determination, the container was allowed to overflow so that no bubbles will be formed inside the container that may affect the amount of DO in the water sample. In the experiment on dissolved oxygen determination, the tips of the pipettes should be well above the surface of the liquid when introducing various reagents into the full bottle of sample. 4. Titration is usually used to standardize a solution. Standardization is the process of determining the exact concentration of a solution.

(A) if both sentences are true, (B) if both sentences are false, (C) if the first sentence is true but the second is false, and (D) if the first sentence is false but the second is true. 1. From the air, oxygen can slowly diffuse across the water’s surface from the surrounding atmosphere, or be mixed in quickly through aeration, whether natural or man-made. The aeration of water can be caused by wind (creating waves), rapids, waterfalls, ground water discharge or other forms of running water. 2. Nuclear energy is synonymous to atomic energy. Uranium is often used as fuel in nuclear reactors because its atoms do not split apart easily. 3. In collecting the tap water sample used in the experiment on dissolved oxygen determination, the container was allowed to overflow so that no bubbles will be formed inside the container that may affect the amount of DO in the water sample. In the experiment on dissolved oxygen determination, the tips of the pipettes should be well above the surface of the liquid when introducing various reagents into the full bottle of sample. 4. Titration is usually used to standardize a solution. Standardization is the process of determining the exact concentration of a solution.