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.
Answer:
96.5 g/ml
Explanation:
If 5g is 19.3 then 25g is 19.3x5 which is 96.5 g/ml
Answer:
um i dont know anything about music sorry
Had to look for the options and here is my answer.
When we say that a redox reaction is spontaneous, this would mean that there is a formation of positive voltage <span>across the electrodes of a voltaic cell. Therefore, the system that this kind of reaction produces electrical energy is in a GALVANIC CELL. Hope this helps.</span>
