Permanent hardness in water is hardness due to the presence of the chlorides, nitrates and sulphates of calcium and magnesium, which will not be precipitated by boiling.
Chlorine, like any other chemical substance, has no hardness unless it is in its solid state. Even then, a temperature would have to be specified for a meaningful answer.
Temporary hardness of water is due to the presence of calcium hydrogentrioxocarbonate(IV) which decompose on heating.when this water is heated calcium trioxocarbonate(iv) is form as insoluble and this brings the ca+ out of the solution as precipitate.once the ca+ re out of the solution soap can now lather well.
Polio and Guillain-Barre syndrome are two diseases that can potentially cause permanent paralysis due to damage to the nerves and muscles. Other conditions such as spinal cord injuries or certain autoimmune disorders can also lead to permanent paralysis.
You can review the site below, to read the ranking of the hardest minerals. Other contributors can add other details to give you additional scientific scales of hardness.
Hardness measures a material's ability to resist permanent deformation, whereas brittleness measures a material's tendency to fail or break without undergoing significant deformation. In other words, hardness relates to the resistance to scratching or indentation, while brittleness relates to the tendency to fracture.
Minerologists identify mineral harness with a variety of tools. In order of hardness, they gnerally use their fingernails, nails, copper pennies, knife blades, glass, porcelain and other minerals such as quartz, topaz, corundum and diamond. The Moh's Hardness Scale gives a list of minerals in order of hardness with talc being the softest with a rating of "1" and diamond the hardest at a "10".
A Diamond is harder than any other natural or artificial substance known, it is ideal for both GEM and industrial purposes. supplement. Diamond is 10 on the Mohs scale of hardness. No other substance is harder, but not all diamonds are equally hard. Some exceptionally (well relatively) hard diamonds come from New South Wales in Australia.
No other gemstone has the hardness of a diamond.
The corrosive label is more harmful because although irritant labels shows us that the substance can cause reddening or blistering to the skin, corrosive subtances can attack and DESTROY tissue, including the eyes and skin.
The Mohs hardness of sodium chloride is 2,5. The Mohs hardness is established by comparison with other minerals, having a known hardness.
The hardness of water is typically measured using the "grains per gallon" (GPG) scale in the United States or the "parts per million" (ppm) scale in other regions. These scales quantify the concentration of minerals, usually calcium and magnesium, that cause water hardness.
Orthoclase has a hardness of 6 on the Mohs scale of mineral hardness. It is a common mineral found in granite and other igneous rocks.