In 1909, rutherford began to notice that alpha particles, when fired at a piece of gold foil, would not always behave in accordance to the plum pudding model of an atom. if j.j. thomson's model of an atom was correct, rutherford should have seen the alpha particles a) bounce directly back at the site of their origin. b) to be stopped by the gold foil and fall to the bottom of the chamber. c) be deflected in a variety of directions while also passing through the gold foil. d) pass directly through the gold foil, hitting the zinc sulfide screen placed behind the foil.

D) pass directly through the gold foil, hitting the zinc sulfide screen placed behind the foil.

Explanation:

Rutherford carried out an experiment in which he bombarded a very thin blade of gold with alpha (α) particles emitted by a sample of polonium (radioactive material), which was inside a lead block with a small hole through which the particles passed.

Gold was chosen because it is an inert, unreactive material. So far, it was believed that the atom would be a positively charged sphere, with electrons (negative particles) evenly distributed throughout its volume, as Thomson's model indicated.

If the atom were really like this, the alpha particles, which are composed of positive particles, would pass through the atoms of the gold slide and, at most, some would deviate slightly in their path as they approached the electrons.

But that is not what Rutherford observed. The vast majority of particles crossed the gold blade, a small amount did not cross the sheet, but returned, and some alpha particles deviated from their trajectories. This proved that Thomson's model was incorrect.

Explanation:

Myelination is the process of generating myelin in neurons. In CNS,  oligodendrocyte make the  myelin sheath.

The main function of myelin is to increase the speed of electrical impulses  along the myelinated fiber.

Myelinated fibers lack voltage-gated sodium channels along the myelinated internodes,  having them only at the nodes of Ranvier though which the molecules moves.

Demyelination is the loss of the myelin sheath,  result due to some neurodegenerative autoimmune diseases, resulting in the decrease of the speed of action potential propagation.