the ratio of parent to daughter = 15.38 : 1
The radioactive disintegration is considered to be first order reaction.
The relation between first order rate constant and the half life is:
Let us calculate the rate constant from half life as
The rate law expression for first order reaction is
A0 = initial amount of rubidium isotope = say 100
At= final amount of rubidium isotope after 4.6 billion years
putting all values
The amount of daughter isotope formed =100-93.897 = 6.103
the ratio of parent to daughter = 93.897:6.103 = 15.38 : 1
More than 75 percent
Let us carefully analyze this problem:
The half life of the rubidium isotope = 50 billion years
The half-life of a radioactive isotope is the time it takes for it to decay to half of its original amount.
Every 50years, we know that a rubidium isotope would split into half.
Initially when the isotope was formed, we would only have the parent atoms there. There wont be any daughter;
ratio of parent to daughter = 100 : 0
When the isotope decays to half; we would have equal number of parent and daughter:
ratio of parent to daughter at half life = 50 : 50
The age of the earth is about 4.6billion years;
x 100 = 9.2% of the half-life of the rubidium isotope.
At this time, we should know that only 9.2 percent of the daughter would have been formed.
The remaining parent would be 100 - 9.2 = 90.8% would still be left undecayed.
The ratio of parent to daughter = 90.8 : 9.2
This is more than 75% of the parent
there all right good
lol for the pointsss
a rubidium isotope has a half-life of almost 50 billion years. given that scient...