Question

( # )
( - ) For why half ( -l i^{circ}+c )
time a quantity decays halt
element in 12 day ( =1-7 / 8=frac{1}{8} )
Remaining elemer( i cdot frac{1}{2} times frac{1}{2} times frac{1}{2} )
3 half
( therefore )
( 12=3 t_{1 / 2} )
( t_{y_{2}}=4 ) the elemant will remain only ( frac{1}{2} )
( therefore )
in 24 day 1 the
ie ( frac{1}{64} )
comet optin is
(3)

# 13 90 TL Half life of a certain radioactive element is such that 7/8 of a given quantity decays in 12 days. What fraction remains undecayed after 24 days? (1) 0 (2) 1/128 (3) 1/64 (4) 1/32

Solution