One gram radium is reduced by 2 milligram in 5 years by `alpha`-decay. Calculate the half period of radium.

Calculate the mass of 2.5gram atoms of calcium?

The atomic weiht of radium is 226 .It is observed that 3.67 xx 10^(10) alpha - particles are emitted per second from one gramp of radium.Calculate in years the half-life period of radium.

Calculate the mass of 2.5 gram atoms of magnesium.

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

Radium decomposes at a rate proportional to the quantity of radium present. It is found that in 25 years, aproximately 1.1% of a certain quantity of radium has decomposed. Determine approximately how long will it take for half of the original amount to decompose? (given log_e(.989)=-0.01106 and log_e 2=0.6931)

Starting from 10g of a radioactive element, 0.25 g was left after 5 years. Calculate Rate constant for the decay of the radioactive element.

The isotopes Radium- 224(_(88)Ra^(224)) and Radium- 226(_(88)Ra^(226)) both undergo spontaneous alpha -particle decay. Radium-224 has a half - life of 3.6 days. Calculate the decay constant of Radium-224.

Starting from 10g of a radioactive element, 0.25 g was left after 5 years. Calculate The amount left after one year.

The half life period of a substance is 60 min at a certain initial concentration. When the concentration is reduced to one half of the initial concentration, the half life period is found to be 30 min. Calculate the order of the reaction.

Uranium - 234 is radioactive and emits alpha -particles at what appears to be a constant rate.A sample of uranium - 234 of mass 2.64 mu G is found to hae an activity of 604 Bq. Calculate for the sample of Uranium -234 the half-life in years.