Questions

Permanent hardness of water may be removed by the addition of Sodium Carbonate.

Photoautotrophs are those organisms that can make their own food using sun light with the help of the process of photosynthesis.

Plants can prepare their own food using sunlight. Hence they are Photoautotrophs.

Expendable properties are those properties that are consume in use or that lose their identity in use. It also include those properties that become an integral part of other property when put to use and those properties which have an expected service life of less than one year.

The Mesoamerican leader Pakal, The great was the king of a Maya city-state in the history.

When backed by buying, power wants become demands. 

Reflection is what which looks back but can't see.

Mercury was the remedy of choice for syphilis in Protestant Europe. Until the early 20th century, the primary treatment for syphilis was mercury, in the form of calomel, ointments, steam baths, pills, and other concoctions.

Mercury was already being used in Western Europe to treat skin diseases.

The ability of two or more substances to combine to form other substances is called Reactivity.