精華區beta NTU-Exam 關於我們 聯絡資訊
課程名稱︰普通化學甲 課程性質︰必修 課程教師︰林萬寅 開課學院:理學院 開課系所︰物理系 考試日期(年月日)︰09.06.03 考試時限(分鐘):15min 是否需發放獎勵金:是 (如未明確表示,則不予發放) 試題 : 1. (236 88)Ra undergoes α-decay to give radon nucleus with a half-life of 1600 years. The mass of each Ra-226 is 226.025402 u and 1u = 1.67*10^-24g 12% (a) Write the nuclear reaction for the decay of Ra-226 to Rn. (b) Find the decay constant k for the first-order decay of Ra-226 (c) Calculate the radioactivity (in Becquerel or disintegrations/s) of 1.00g Ra-226 (d) What volume of Radon (Rn-222) will be produced per day at STP from 1.00g of Ra-226? 2. A rock contains 280μmol (238 92)U (t1/2 = 4.5*10^6 yr) and 120μmol (206 82)Pb. Assume that all the Pb-206 comes from decay of U-238 8% (a) Estimate the age of the rock. (b) How many α and β decays are involved in the decay series of U-238 to Pb206? -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 118.168.41.205