Mercury have the lowest melting point among metals.

A metallic bond is characterized by free electrons and generally forms a specific geometric pattern of compact arrangement of atoms. All metals (except mercury) thus exist in a solid state at room temperature and have a specific crystal structure. Mercury belongs to the zinc group of elements in the periodic table, which comprises zinc, cadmium and mercury. They all have completely filled-up atomic orbitals. It becomes difficult to knock out these electron(s) from their orbitals and form metallic bonds. Therefore, they are soft (low melting point) and do not show multiple valence states unlike other transitional or rare earth metals. In mercury, the binding energy of outer electrons (towards nucleus) is highest and no electron is available to participate in metallic bond formation. Therefore, mercury does not have a specific crystal structure and is the only metal which is liquid at room temperature with a melting point of -38 degree Celsius.

Distilled water doesn't conduct electricity..

Distilled water does — but very little compared to piped, well or salt water. The reason is that the way a liquid conducts electricity is by the positively or negatively charged ions that are actually moving from one of the electrodes to the other, carrying charge (electricity) with them. Salt water has salt in it, NaCl, which readily ionizes or dissociates to ions of Na+ and Clthat can float through the water carrying charge and thus conduct electricity. Distilled water is water that was boiled to steam and recondensed to water. So distilled water is relatively pure H2O. Water can ionize to H+ and OH- like salt does, but it ionizes to a far lesser degree and is very resistant to conducting electricity.

Orgin of +, - etc symbols...

The earliest print appearance of the modern signs seem to come from a book on Mercantile Arithmetic by Johannes Widmann in 1489, used to indicate surpluses and deficits. The + is a simplification of the Latin “et” (comparable to the ampersand - &). Widmann referred to the symbols - and + as minus and mer. According to the ‘Earliest Uses of Various Mathematical Symbols’ website, a book published by Henricus Grammateus in 1518 used the symbols. Robert Recorde, the designer of the equals sign, introduced plus and minus to the UK in 1557 in The Whetstone of Witte.

Mineral water contain...

Naturally available water, after having come in contact with various salts found in soil stratas and atmosphere, contains a large number of chemicals. Some of them are calcium, magnesium, potassium, sodium, iron, sulphates, nitrates, nitrites, phosphates and oxygen. Small quantities of these substances are responsible for the taste and odour of natural water and are useful for essential functioning of the human body. Very small quantities of copper, chromium, chlorine, fluorine, arsenic, lead, cadmium, mercury and selenium are also found, depending upon the chemistry of the soil.

sungrazer..

When comets break up, smaller comets and sungrazers are formed. As these approach the sun, they break into smaller fragments before colliding into it. Sungrazers are classified into families and the largest is the Kreutz family, with over 500 sungrazers. It was discovered by Heinrich Kreutz, a 19thcentury German astronomer who found that some sungrazers came from a larger comet that broke up 12,000 years ago.

"similia similibus curantur" ?

‘Similia similibus curantur’ is a phrase coined by Dr Samuel Hahnemann, the founder of homoeopathy. Nearly 180 years ago, he did an experiment with a drug decoction made from the bark of the chincona tree, known for its curative properties in the treatment of malaria. He drank the decoction, though he was healthy, and developed the symptoms of malaria. This made him believe that a drug which possesses the property of curing an ailment can create symptoms of the disease in a healthy person who takes the drug in large doses.

Jack of all trades means

‘Jack of all trades, master of none’ is a figure of speech used with reference to a person who is competent with many skills but is not outstanding in any particular one. The phrase was in common use during the 1600s and was used as a term of praise. ‘Jack’ in those days was a generic term for ‘man'. Later, the ‘master of none’ was added and the expression ceased to be flattering.

Zodiac signs named after Animals

The term ‘zodiac’ stands for animals. However, all zodiac signs do not represent animals, like Libra is represented by a balance. Astrologically and astronomically, zodiac signs are representative of various pattern formed by stars. Ancient astronomers had named each zodiac by the shape formed by a few important and bright stars resembling the shape of animals, located in that section of the sky.