Q27.Substance A has atomic mass number 16 and half life of 1 day. Another substance B has atomic mass number 32 and half life of 21 day. If both A and B simultaneously start undergo radio activity at the same time with initial mass 320 g each, how many total atoms of A and B combined would be left after 2 days (1) 3. 38 × 1024 (2) 6. 76 × 1024 (3) 6. 76 × 1023 (4) 1. 69 × 1024
What This Question Tests
This question involves calculating the number of atoms remaining for two different radioactive substances after a given time, requiring the application of the radioactive decay law and conversion from mass to number of atoms.
Concepts Tested
Formulas Used
N = N0 (1/2)^(t/T)
N0 = (mass / atomic_mass) * N_A
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13.5 The Q value of a nuclear reaction A + b ® C + d is defined by Q = [ mA + mb – mC – md]c2 where the masses refer to the respective nuclei. Determine from the given data the Q-value of the following reactions and state whether the reactions are exothermic or endothermic. (i) 11 H+13 H →12 H+12 H (ii) 126 C+126 C →1020 Ne+ 24 He Atomic masses are given to be m ( 12 H ) = 2.014102 u m ( 13 H) = 3.016049 u m ( 126 C ) = 12.000000 u m ( 1020 Ne ) = 19.992439 u
📋 Question Details
- Chapter
- Nuclei
- Topic
- Radioactivity
- Year
- 2023
- Shift
- 29 Jan Shift 2
- Q Number
- Q27
- Type
- MCQ
- NCERT Ref
- Class 12 Physics Ch 13: Nuclei
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