Iodine-131 is a radioactive material that plays a role in natural gas production and has a half-life of 8 days. A 320-mg sample of iodine-131 will decay to 250 mg after approximately days.

Time of decays approximately 2.853 days

Further explanation

Given

mass = 320mg iodine-131

No=320 mg

Nt=250 mg

t1/2 = 8 days

Required

t=time of decays

Solution

General formulas used in decay:  

Input the value

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