19. which of the following is not required characteristic of all minerals? characteristic chemical composition b. inorganic c. naturally occurring d. crystalline solid e contain silica tetrahedra

:calculate the sum of the interior angles of a 13-sided polygon.

What was the most difficult obstacle to overcome in the creation of an autonomous state after indian independence was achieved? a british willingness to go to war to retain the region b. religious differences between hindus and muslims c. ethnic differences between tribal regions d. indian princes' inability to decide on a format of government

What does 2[tex] {2}^{ - 4} \times {2}^{ - 2} [/tex]