Radium decomposes at a rate proportional to the quantity of radium present. It is found that in 25 years, approximately 1.1% of a certain quantity of radium has decomposed. Determine approximately how long it will take for one-half of the original amount of radium to decompose? [Given`(log)_e 0.989=0. 01106a n d(log)_e2=0. 6931` ]

If is given that radium decomposes at a rate proportional to the amount present. If p % of th original amount of radium disappears in l years, what percentageof it will remain after 2l years?

Experiments show that radium disintegrates at a rate proportional to the amount of radium present at the moment. It's half life is 1590 years. What percentage will disappear in one year? [Use e^(-log2/1590)=0. 9996 ]

Experiments show that radius disintegrates at a rate proportional to the amount of radium present at the moment. Its half life is 1590 years. What percentage will disappear in one year? [Use e^(-log2/1590)=0. 9996 ]

The thermal decomposition of HCO_2 H is a first order reaction with a rate constant of 2.4 xx 10^(-3) s^(-1) at a certain temperature. Calculate how long will it take for three-fourth of initial quantity of HCO_2 H to decompose. (log 0.25 =-0.6021)

The thermal decomposition of formic acid (HCOOH) is a first order reaction with the rate constant of 2.4 xx 10^(-3)s^(-1) at a certain temperature.Calculate how long will it take for three-fourth of initial quantity of HCOOH to decompose.

A radioactive substance disintegrates at as rate proportional to the amount of substance present. If 50% f the given amount disintegrates in 1600 years. What percentage of the substance disintegrates i 10 years ? (-log2)/(160)T a k ee=0. 9957

The rate of increase in the number of bacteria in a certain bacteria culture is proportional to the number present. Given the number triples in 5 hrs., find how many bacteria will be present after 10 hours. Also find the time necessary for the number of bacteria to be 10 times the number of initial present. [Given log_e3=1. 0986 ,\ e^(2. 1972)=9 ]

The activity of 1 g radium is found to be 0.5. Calculate the half-life period of radium and the time required for the decay of 2 g of radium to give 0.25 g of radium (atomic mass off radium = 226).