Thallium-208 has a half-life of 3 minutes. How long will it take 60.0 g of thallium-208 to decay so that 15.0 g of the thallium-208 remains? 3 minutes
6 minutes
9 minutes
12 minutes

Speed is the ratio of the distance of an object moves to

How dose plate tectonics effect climate

Imagine a self-reactive t cell that has not undergone clonal deletion in the thymus (that is to say, it has escaped central tolerance). if it encounters self antigen in the absence of an infection or inflammation, what will happen to this self-reactive t cell? (select two answers) (a) the t cell undergoes clonal expansion. (b) the t cell gains effector functions. (c) the t cell undergoes apoptosis. (d) the t cell becomes activated. (e) the t cell becomes anergic.