Why have there been so many revisions to the atomic model? under what circumstances should the atomic model be revised again?
(its 2 questions all together on this one)

Which notation is used to represent an alpha particle? a. b. c. d.

How do the kidneys affect homeostasis

Ametal ring 4.20 cm in diameter is placed between the north and south poles of large magnets with the plane of its area perpendicular to the magnetic field. these magnets produce an initial uniform field of 1.12 t between them but are gradually pulled apart, causing this field to remain uniform but decrease steadily at 0.240 t/s . (a) what is the magnitude of the electric field induced in the ring? (b) in which direction (clockwise or counterclockwise) does the current flow as viewed by someone on the south pole of the magnet?