Calculate the ratio of [Ca2+][Ca2+] to [Fe2+][Fe2+] in a lake in which the water is in equilibrium with deposits of both CaCO3CaCO3 and FeCO3FeCO3. Assume that the water is slightly basic and that the hydrolysis of the carbonate ion can therefore be ignored.

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