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Water may be one of the most abundant compounds on Earth, but it is also the most mysterious. Like most liquids, it becomes denser as it cools. But unlike them, it reaches a state of maximum density at 4 degrees Celsius, then decreases in density as it freezes.

In solid form, it is even less dense, the major reason why standard ice floats on water. This is one reason life on Earth flourished. If ice were denser than water, lakes and oceans would freeze solid from the bottom up, preventing life from happening in the way we know it.

A current unsolved mystery about water is known as the Mpemba Effect. The phenomenon is named after a Tanzanian student who in 1963 observed that hot ice cream mix freezes faster than cold. These same observation about the rate at which water freezes were also made by classical scientists such as Aristotle, Bacon, and Descartes. Mpemba published a short article announcing his ideas, but he had no experimental evidence to back up the thoughts.

A researcher decides to complete an experiment to add to the body of knowledge concerning the Mpemba effect. He decides to obtain samples of pond water, lake water, and distilled water. The water samples are divided into a series of containers. Each container is the same size and shape and a graduated cylinder is used to place equal volumes of water into each vessel. The water in the containers is then heated or cooled to reach its prescribed starting temperature. Each container was then placed into a -30 degree Celsius freezer. The containers were inspected every five minutes and the time for the water to freeze to solid ice was recorded. Data was recorded in the following chart:

Type of Water: Distilled Pond Lake
Starting Temperature (Celsius) Time to Freeze (min) Time to Freeze (min) Time to Freeze (min)
5 70 63 64.5
10 70 62.5 64
15 69 60 61
20 65.4 59.6 60.4
25 62 57 59
30 58.7 54.5 58.2

The scientific community applauds the researcher for his thorough work. There is however, no widespread acceptance of the Mpemba effect.

Which statement most accurately reflects the next step in garnering more acceptance for this idea?


Present the findings at multiple conferences until it is accepted by the scientific community.


Repeat the experiment multiple times with a wide variety of samples and see if the results are similar.


Test distilled water at more temperatures and analyze the data.


Design an experiment using ocean water as a control, comparing the results of various types of distilled water.

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