In which properites , the activity of a radioactive sample depends ?

What do you mean by 'activity' of a radioactive sample ?

Use of radioactivity.

The initial number of radioactive atoms in a radioactive sample is N_0 . If after time t the number of becomes N, then N=N_0e^(-lambdat) , where lambda is known as the decay constant of the element. The time in which the number of radioactive atoms becomes half of its initial number is called the half-life (T) of the element. The time in which the number of atoms falls to 1/e times of its initial number is the mean life (tau) of the element. The product lambdaN is the activity (A) of the radioactive sample when the number of atoms is N. The SI unit of activity is bequerel (Bq)' where 1 Bq= 1 decay. s^(-1) . After how many days the activity of Iodine-131 will be 1/16 th of its initial value. [The half-life of Iodine-131 is 8 d.] (A) 24 d (B) 32 d (C) 40 d (D) 48 d

The initial number of radioactive atoms in a radioactive sample is N_0 . If after time t the number of becomes N, then N=N_0e^(-lambdat) , where lambda is known as the decay constant of the element. The time in which the number of radioactive atoms becomes half of its initial number is called the half-life (T) of the element. The time in which the number of atoms falls to 1/e times of its initial number is the mean life (tau) of the element. The product lambdaN is the activity (A) of the radioactive sample when the number of atoms is N. The SI unit of activity is bequerel (Bq)' where 1 Bq = 1 decay. s^(-1) . The half-life of Iodine-131 is 8 d. What is the activity (in Bq) of 1 g of Iodine? (A) 2.3xx10^15 (B) 4.6xx10^15 (C) 6.9xx10^15 (D) 9.2xx10^15

The initial number of radioactive atoms in a radioactive sample is N_0 . If after time t the number of becomes N, then N=N_0e^(-lambdat) , where lambda is known as the decay constant of the element. The time in which the number of radioactive atoms becomes half of its initial number is called the half-life (T) of the element. The time in which the number of atoms falls to 1/e times of its initial number is the mean life (tau) of the element. The product lambdaN is the activity (A) of the radioactive sample when the number of atoms is N. The SI unit of activity is bequerel (Bq)' where 1 Bq = 1 decay. s^(-1) , and Avogadro's number, N=6.023xx10^23 What is the ratio of activity of same amount of sodium-24 to that of iodine-131? [half life of sodium-24 is 15h.] (A) 1/70 (B) 1/7 (C) 7 (D) 70

The initial number of radioactive atoms in a radioactive sample is N_0 . If after time t the number of becomes N, then N=N_0e^(-lambdat) , where lambda is known as the decay constant of the element. The time in which the number of radioactive atoms becomes half of its initial number is called the half-life (T) of the element. The time in which the number of atoms falls to 1/e times of its initial number is the mean life (tau) of the element. The product lambdaN is the activity (A) of the radioactive sample when the number of atoms is N. The SI unit of activity is bequerel (Bq)' where 1 Bq = 1 decay. s^(-1) , The half-life of Iodine-131 is 8d. Its decay constant (in SI) is - (A) 10^(-6) (B) 1.45xx10^(-6) (C) 2xx10^(-6) (D) 2.9xx10^(-6)

The initial number of radioactive atoms in a radioactive sample is N_0 . If after time t the number of becomes N, then N=N_0e^(-lambdat) , where lambda is known as the decay constant of the element. The time in which the number of radioactive atoms becomes half of its initial number is called the half-life (T) of the element. The time in which the number of atoms falls to 1/e times of its initial number is the mean life (tau) of the element. The product lambdaN is the activity (A) of the radioactive sample when the number of atoms is N. The SI unit of activity is bequerel (Bq)' where 1 Bq = 1 decay. s^(-1) . The half-life of Iodine-131 is 8 d. Its mean life (in SI) is - (A) 4.79xx10^5 s. (B) 6.912xx10^5 s. (C) 9.974 xx 10^5 s. (D) 22.96xx10^5 s.

Statement I: At any specific instant, the activity of radium-226 is less than Polonium-210 for equal mass of sample because the half-life of radium and that of polonium are 1600 y and 140 d respectively. Statement II: The activity of a radioactive sample is proportional to its decay constant. (A) Statement I is true, statement II is true, statement II is a correct explanation for statement I. (B) Statement I is true, statement II is true, statement II is not a correct explanation for statement I. (C) Statement I is true, statement II is false. (D) Statement I is false, statement II is true.

Define the Activity of a radioactive sample. Write its S.I. unit. A radioactive sample has activity of 10000 disintegrations per second (dps) after 20 hours. After next 10 hours its Activity reduces to 5000 dps. Find out its half-life and initial activity.

The activation energy of a reaction depends on -