A solution contains a mixture of two isotopes A (`half-life=10days`) and B (`half-life=5days`). Total activity of the mixture is `10^10` disintegration per second at time `t=0`. The activity reduces to `20%` in `20 days`. Find (a) the initial activities of A and B, (b) the ratio of initial number of their nuclei.
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Ammonia contains 82.32% of nitrogen and 17.65 % of hydrogen . Water contains 88.90% of oxygen and 11.10% of hydrogen . Nitrogen trioxide contains 63.1
In `NH_(3), 17.65 g` of H combine with N=82.35 g `therefore` 1 g of H combine with H`=(82.35)/(17.65) g` =4.66 g In `H_(2)O, 11.10 g` of H combine with O=88.90...
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A sample of oxygen contains `O^(16) & O^(18)` isotopes only with percentage abundance respectively as 90% & 10% in terms of mole. Identify the correct
Correct Answer - A::B::D (A) Average atomic mass `=(M_(1)n_(1)+M_(2)n_(2))/(n_(1)+n_(2))=(16xx90+18xx10)/(100)=16.2` (B) Average number of protons `=(8xx90+8xx10)/(100)=8` (C ) Average number of neutrons `=(8xx90+10xx10)/(100)=8.2`
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A sample contains two isotopes -one stale and the other unstable. Number of stable nuclei is equal to `N_(s)` and number of unstable nuclei is equal t
Correct Answer - `N_(s)//N_(u)=1//3`
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A radioactive sample consists of two isotopes one of then decays by `alpha-` emission with a half life of `tau_(1)=405s` and the other one decays by `
Correct Answer - (a) `(1)/(9)` (b) 1215s
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The half lives of two longest-lived radioactive isotopes of phosphorus `P^(32)` and `P^(33)`, are 14 days and 28 days respectively. A sample has been
Correct Answer - 0.3mCi
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Natural Chlorine is found to be a mixture of two isotopes of masses 34.98 a.m.u and 36.98 a.m.u. respectively. Their relative abundances are 75.4 and
Correct Answer - 35.47 amu
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A sample of Uranium is a mixture of two isotopes `._(92)^(234)U` and `._(92)^(238)U` present in the ratio `10%` and `90%` by weight. The half lives of
Correct Answer - `[16.67% and 83.33 %]`
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The half-life of `Au^198` is 2.7 days.(a) Find the activity of a sample containing `1.00 mu g ` of `Au^198`.(b) What will be the activity after 7 days
Correct Answer - [(a) `0.244 Mci, 0.04 Mci` (b) `T_(1//2) = 48 min`]
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175 litres of a solution contains `88%` of acid and the rest water. How many liters of water must be added such that the resulting mixture contains `2
Correct Answer - 25 litres
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A man travels half time of its journey with speed of 5m/s and for remaining half time he moves half of its total distance travelled, with speed of 3 m
Correct Answer - 4.5 m/s
2 Answers 1 views