Two different radioactive elements with half-lives `T_1` and `T_2` and `N_1` and`N_2` (undecayed) atoms respectively present at a given instant. Determine the ratio of their activities at this instant.

At any instant, the ratio of the amount of radioactive substance is 2:1. If their half lives be respectively 12 and 16 hours, then after two days what will be the ratio of the substances?

Two radioactive nuclei X and Y initially contain an equal number of atoms.Their half life is 1 hour and 2 hours respectively.Calculate ratio of their rates of disintegration after two hours.

If k_1 and k_2 are rate constants at temperatures T_1 and T_2 respectively, then according to Arrhenius equation,

A radioactive isotope has a half-life of T years. How long will it take the activity to reduce to - 1% of its original value?

Radioactive disintegration is a first order reaction and its rate depends only upon the nature of nucleus and does not depend upon external factors like temperature and pressure. The rate of radioactive disintegration (Activity) is represented as -(dN)/(dt)=lambdaN Where lambda= decay constant, N= number of nuclei at time t, N_(0) =intial no. of nuclei. The above equation after integration can be represented as lambda=(2.303)/(t)log((N_(0))/(N)) Calculate the half-life period of a radioactive element which remains only 1//16 of its original amount in 4740 years: a) 1185 years b) 2370 years c) 52.5 years d) none of these

Define the following terms : Half life period of reaction (t_(1//2)) .

For a partiocular reaction with initial conc. Of the rectents as a_(1) and a_(2) , the half-life period are t_(1) and t_(2) respectively. The order of the reaction (n) is given by :

A radioactive sample can decay by two different processes .The half-life for the first process is T_1 and that for the second process is T_2 . Show that the effective half-life T of the nucleus is given by 1/T=1/(T_1) + 1/(T_2) .

The ratio of activities of two ratio niculides X and Y in a mixture at time t=0 was found to be 4:1 After two hours, the ratio activities become 1:1 . If the t_(1//2) of radio nuclide X is 20 min then t_(1//2) [in mintes] of ratio nuclide Y is , a) 10 b) 20 c) 30 d) 40

Two perfect gases at absolute temperatures T_1 and T_2 are mixed. There is no loss of energy. Find the temperature of the mixture if the masses of the molecules are m_1 and m_2 and the number of the molecules in the gases are n_1 and n_2 respectively.