Final answer:
Distilled water is considered pure because the distillation process removes the majority of impurities, including minerals, bacteria, and chemicals. While filtered and chlorinated water are treated for safety, they still contain dissolved substances and are not considered pure.
Step-by-step explanation:
Among the types of water mentioned, distilled water would be considered pure. Distillation involves boiling the water to produce water vapor and then condensing it back into a liquid in a separate container. This process removes impurities including salts, bacteria, and other substances, effectively producing pure H2O. Filtered water and bottled water may have fewer impurities than tap water, but they still can contain various dissolved substances. Chlorinated water, while disinfected to kill bacteria, contains chlorine and potentially other disinfection byproducts, and therefore cannot be considered pure water.
Water for drinking, often referred to as potable water, must meet certain regulations and standards to ensure it does not contain harmful levels of chemical pollutants or microorganisms. Water purification methods, including distillation, are employed to make water safe for consumption. Despite these purification methods, it is important to note that in nature, there is no such thing as absolutely pure water, as all water contains some level of dissolved substances.