The nuclei P and Q have equal number of atoms at t = 0. Their half-lives are 3 hr and 9 hr respectively. Compare their rates of disintegration after 8 hour from the start.

What is meant by pseudo unimolecular reaction. Explain with an example. 0.0625g remains from 1g of a radioactive element after 20 years of radioactive decay. Determine the rate constant and half-line (t1/2) of the reaction. How much of the element did remain after 10 years from the start.

0.0625g remains from 1g of a radioactive element after 20 years of radioactive decay. Determine the rate constant and half-life (t_(1//2)) of the reaction. How much of the element did remain after 10 years from the start?

What is meant by pseudo unimolecular reaction? Explain with an example. 0.0625 g remains from 1 g of a radioactive element after 20 years of radioctive decay. Determine the rate constant and half-life (t_(1//2) of the reaction. How much of the element did remain after 10 years from the start?

Two radioactive nuclei P and Q in a given sample decay into a stable nucleus R. At time t=0, number of P species are 4N_0 and that of Q are N_0 . Half-life of P (for conversion to R) is 1 min whereas that of Q is 2min. Initially there are no nuclei of R present in the sample. When number of nuclei of P and Q are equal, the number of nuclei of R present in the sample would be

Dissociation reaction of PH_3 at 120^@C is as follows. 4PH_3(g) rarr P_4(g) + 6H_2(g) . Write equation for the reaction and half life period for rate = K[PH_3] and 37.9 see respectively. How much time required for 3/4 part dissociation? How much part remain undissociated after 1 minute.

Two radioactive substances A and B have decay constants 5lamda and lamda respectively. At t-0, they have the same number of nuclei. The ratio of number of nuclei of A to that of B will be (1//e)^(2) after a time interval of

The position-time (x-t) graphs for two children A and B returning from their school O to their homes P and Q respectively are shown in Fig. Choose the correct entries in the brackets below , (a) (A/B) lives closer to the school than (B/A) (b) (A/B) starts from the school earlier than (B/A) (c) (A/B) walks faster than (B/A) (d) A and B reach home at the (same/different) time (e) (A/B) overtakes (B/A) on the road (once/twice).

P and Q are two elements which form P_2Q_3 and PQ_2 molecules. If 0.15g mole of each weighs 15.9g and 9.3g respectively. What are the atomic masses of the elements P and Q.

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

An A.P. consist of even number of terms 2n having middle terms equal to 1 and 7 respectively. If n is the maximum value which satisfy t_(1)t_(2n)+713 ge 0 , then the value of the first term of the series is