This is because only radiation can pass through the lead plate.1A1A1A(d)Handle the radioactive sources with forceps.1AKeep the radioactive sources at arm’s length, and point it away from the human body.(Or other reasonable answers)1A3SolutionsMarks(a)(i)This can produce a narrow beam of particles.1A(ii)particles take path B.1Aparticles carry positive charges and are deflected along the direction of the electric field.1A1A
LQ_Radiation(b)(i)(Correct path of )(Correct path of )1A1A(ii)(Xbends upwards)(Xis deflected by a larger amount than particle)1A1A(c)(i)An source causes less serious damage than a source if both of them are placed outside the body.1AThis is because the penetrating power of radiation is very weakand only a very small amount of the radiation can enter the body.1A1A(ii)An source causes more serious damage than a source if both of them are inside the body.1AThis is because radiation has much stronger ionizing power.Therefore, it causes more serious damage to the body cells.1A1A4SolutionsMarks(a)(i)Any two of the following:Cosmic rays from outer spaceNatural radioactive substances in living bodies, and food and drinksRadioactive gases given off from rocks, soil and building materials(Or other reasonable answers)2 1A(ii)This is because radiation from a radioactive source is emitted at random.1A
LQ_Radiation(iii)radiation can be stopped by a piece of paper, radiation can be stopped by 5 mm of aluminium, and radiation can be partially absorbed by 10 mm of lead.
- Fall '19
- Radioactive Decay, Ionizing radiation, Radioactive contamination, Background radiation, actual count rate