When the powder of a common metal is heated in an open china dish, its color turns black however when hydrogen I sassed over hot black substance so formed, it regains its original color based on the given information answer the following question a)what type of chemical reaction takes place in each of the two given steps? write a balanced chemical reaction for both in the reaction.
b)name the metal initially taken in the powdered form

Wind will blow from one direction to another.

The  grandmother cell  is a hypothetical  neuronthat represents a complex but specific concept or object.[1]  it activates when a person "sees, hears, or otherwise sensibly discriminates"[2]  a specific entity, such as his or her grandmother. the term was in use at least as early as 1966 amongst staff and students in the department of experimental psychology, university of cambridge, england. a similar concept, that of the  gnostic neuron, was proposed two years later