so i have an exam tomarrow and i dont even know these true n false i cant find them on the packet i got... and getting a bit mad.

true or false?

37. gravitational forces are greater then electrical forces?

38. nuclear forces must be stronger than electrical repulsive forces between nucleons in order to hold a nucleus togather?

39. most nuclei are stable?

40. in a stable nuclei the gravitational force betweem nucleons is sufficiently strong to overcome electrostatic repulsion?

41. a radioactive atom of uranium divides into two particles which are about equally unstable?

42. the two main fragments produced by nuclear fission have approximately the same mass?

43. nuclear fission reaction is the opposite of the nuclear fusion reaction?

44. on earth nuclear fission is necessary in order to trigger a nuclear fusion reaction?

45. nuclei having large masses ( larger than 50 amu) contain many positive charges, and there fore cannot easily undergo fusion?

46. radioactive cobalt is often used to kill cancer cells.?

47. iodine 130 can be used to determine the size, location, and activity of the thyroid gland.?

48. beta particles can supply power to remote locations.?

49. radiation is used to cause genetic mutations in plant and animals.?

50. nuclear fusion is used in the production of electrical power.?

51. an ounce of uranium matter converted to energy in a nuclear reactor could produce as much electricity as could 200,000 pounds of coal.

52. one of the biggest problems with nuclear enegery is the residual radioactivity of spent nuclear fuel.



please help me out im trying to figure these out aswell in my packet is fursrating.. and to the people that help me i will give d2 items if you play..

This post was edited by iNico on Jul 12 2011 07:50pm

google it

37. F (electrical forces are WAY WAY stronger)
38. T (obviously, since electric forces in the nucleus are all repulsive since everything is positively charged or neutral)
39. T
40. F (it's not gravity that keeps the nucleus together)
41. I think it's false. U-235 decays into Th-231 and an alpha particle, and I don't think an alpha particle is radioactive.
42. F (like with U-235, its two products have a mass of 4 and 231)
43. Fission is the splitting of heavy elements and Fusion is the combining of light elements. I would probably say False since the question's wording seems to imply that the products of a fission reaction can simply undergo fusion and you'd be left with what you started with, but that doesn't just happen.
44. F (We've done it with arrays of lasers. Hydrogen bombs set off a fission reaction in order to achieve the temperatures required for fusion, however)
45. I'd say it's probably True. Fun fact: Iron is the largest element that can naturally undergo fusion in the core of a star because the average energy per nucleon is highest in Iron. All larger elements were created in supernovas.
46. Google it, 2 seconds.
47. Google it, 2 seconds.
48. T (A beta particle is an electron, the charge carrier used in electric circuits)
49. T (radiation certainly can cause genetic mutations)
50. F (Fission is used in nuclear power plants. Fusion would be far more efficient, but at present we need to put a lot more energy into the reaction than we are currently getting out of it)
51. Google it. It's probably True though.
52. T

that is what you defiantly should do... researching the answers yourself prepares you a lot more for an exam than if you just try to memorize the answers.

god ya ! vouch

2fg per

The answer is correct, the logic isn't. Fission =/= alpha decay. But it CAN split into, for instance, Barium-140 and Krypton-95, both of which are ultra-unstable.

I know #37 is false... gravity is by far one the weakest force

Ahh right, thanks. I just sort of banged them out quickly and didn't stop to think that it's just alpha decay and not fission into Thorium and Helium, lmao