Half-life of a radioactive substance is the time required to reduce the amount of substance to half of its initial amount.
In present case, half-life is material is given as 1000 years and initial amount of material is given as 400 kg
Answer 1) Since, half-life of radio-active substance is 1000 years, therefore after 1st half life, amount of the material will be left to half the initial amount. Hence, amount of substance left after 1000 years = 400/2 = 200 kg.
Answer 2) For 2000 years, radioactive material has crossed 2 times the half life. Therefore , amount of the material will be left to 1/4 the initial amount. Hence, amount of substance left after 2000 years = 400/4 = 100 kg.
Answer 3) For 4000 years, radioactive material has crossed 4 times the half life. Therefore , amount of the material will be left to 1/16 the initial amount. Hence, amount of substance left after 4000 years = 400/16 = 25 kg.
Base on your question where a concentration cell consist of two SN/SN2+half cells. The solution in one half cell A is 0.13M SN(NO3)2 and is 0.87 M Sn(NO3)2 in the other half cell to get the cell potential at 25 degree the answer is 0.059/2 log0.13/0.87
Answer:
Heyo (Ish Mash Potato) XD
Explanation:
a freighter carrying a cargo of uranium hexafluoride sank in the english channel in 1984. the cargo of uranium hexafluoride weighed 2.25x10 to the eight power. kg and was contained in 30 drums, each having a volume of 1.62x10 to the sixth power L. what is the density in g/ml, of uranium hexafloride.
Hope Mr. Mash Potato Helped!!!
Answer:
yes answer os Na because it's electronic configuration is 1s^2,2s^2,2p^6,3s^1
