Mpemba Effect.

Chapter twenty one a team of scientists finally think they have solved the mystery and think the secret lies in the unique properties of the bonds that hold water atom together. 
Hydrogen bonds bring individual water molecules into close contact, which triggers natural repulsion between the water molecules and causes the bonds between oxygen and hydrogen atoms to stretch as well as store energy. So as the liquid warms, it makes the water molecules sit further apart from each other as the hydrogen bonds stretch. When the molecules shrink again and give up their energy, this  results in it cooling, which the scientists say means that warm water cools faster than cold water and explains the Mpemba effect.
To prove their theory, the chemists calculated the size of the extra cooling caused by the molecular activity and showed that it accounts for the observed differences between the freezing of hot and cold water in experiments. However, some physicists have noted that the explanation cannot currently be used to predict new properties of water that could be created by shortening covalent bonds, for example so there is one step to go before the mystery is satisfactorily solved it also means heat exchangers can be controlled more efficiently as with turbines and a range of applications so of which used in space mining as etching frying water off the optimum point as this fluctuation range calculated as cooling efficiency. 'cool energy calculator'. space cruising would have it, could be a first redesign of smart asteroids maintenance probes. 

This graph shows how the Mpemba effect - how hot water freezes faster than cold. It shows how rapidly boiling water cools compared to the water that starts off at a lower temperature. The Mpemba effect - why hot water freezes more quickly than cold water - is named after a Tanzanian student who took cookery classes in the 1960s and found a hot ice cream mixture froze faster than a cold one.But the strange behaviour of freezing water has been noted by great thinkers throughout history, including Aristotle and Descartes. 
Scientists have tried to explain the Mpemba effect before and theories included the idea that warm containers made better thermal contact with freezes to conduct heat faster and that as warm water evaporates more swiftly, it cools the water, which allows it to freeze faster. But a study led by Xi Zhang at the Nanyang Technological University in Singapore, said the reason for the Mpemba effect is down to the unique properties of the molecular bonds that hold water together, 'Physics Blog Reported'. 
A single water molecule is made from a large oxygen atom joined to two hydrogen atoms with covalent bonds (a chemical bond that involves the sharing of two electron pairs between atoms).But when a hydrogen atom in one molecule drifts close to an oxygen atom in another water molecule, it bonds with it, creating what is called a hydrogen bond. It is these hydrogen bonds that behave in a peculiar way and have attracted the attention of the researchers.
Research study led by Xi Zhang at the Nanyang Technological University in Singapore, said the reason for the Mpemba effect - why hot water freezes more quickly than cold - is down to the unique properties of the bonds that hold water molecules together. The strange behaviour of hot water freezing more quickly has been noted by great thinkers throughout history, including Aristotle (pictured) and Descartes Strangely, while hydrogen bonds are generally weaker than covalent bonds, they are stronger than the 'van der Waals' force' that is the sum of the attractive forces between molecules other than those due to covalent bonds.

Chemists have long suspected the hydrogen bonds were what gives water some strange properties and enables its boiling point to be much higher than other liquids composed of similar molecules - this was because the hydrogen bonds hold it together so well. Research into the exact roles the hydrogen bonds play have been investigated by scientists who have recently found water molecules restricted into tiny tubes form chains and are linked together by hydrogen bonds.
It is these tiny chains that enable a plant to pull water molecules up through its roots.But now Dr Zhang's team believe these bonds explain the Mpemba effect, as the hydrogen bonds bring individual water molecules into close contact, which triggers natural repulsion between the molecules and causes the covalent bonds between oxygen and hydrogen bonds to stretch as well as store energy.So as the liquid warms, it makes the water molecules sit further apart from each other as the hydrogen bonds stretch.