1. Hematite is an ore of iron. It is commonly found in stones and soil. The largest quantity of iron in the earth is found in the form of hematite.

2. The chemical formula of hematite is Fe2O3. It is a heavy and relatively hard oxide mineral.

  3. Its colour ranges from black to steel or silver-grey, grey to brown or reddish.

4. Hematite is used in the production of iron. It is an important mineral that is found in many countries around the world.

(A) to - The correct phrase is "impossible to guess."

The term "Rh factor" is derived from the Rhesus monkey, in which the protein was first discovered. The Rh factor is a protein that can be present on the surface of red blood cells, and it is named after the Rhesus monkey because the protein was initially identified in Rhesus monkey blood during scientific experiments. The Rh factor is an important component in blood typing and can be either Rh-positive (presence of the protein) or Rh-negative (absence of the protein) in humans.

 Article 15 of the Indian Constitution deals with the prohibition of discrimination against any citizen on grounds of religion, race, caste, sex or place of birth. It states that the State shall not discriminate against any citizen on grounds only of religion, race, caste, sex, or place of birth.