Because some decompose and are gone forever.
Answer:
The inner core of Mercury is the same size as Earths core
Explanation:
i think
Ti is B:forames
gjg dkhgfdshkdks
Answer:
Allele frequency
Normal allele 
Mutant r allele 
Genotype frequency
Homozygous normal bugs 
Homozygous mutant bug 
Heterozygous normal bug with one mutant r allele and one normal allele 
Explanation:
It is given that 99% of the bugs were killed after the spray of pyrethrum. This suggests that 1% of the bugs that were not killed must be homozygous for the mutant type allele "r"
Thus, the frequency of homozygous "rr" species i.e 
From this we can evaluate the frequency of mutant "r" allele.
Thus, 

As per Hardy-Weinberg first equilibrium equation, 
Substituting the value of q in above equation, we get

Thus, the frequency of homozygous normal bug is equal to

As per Hardy-Weinberg second equilibrium equation-

Substituting all the available values we get -

Allele frequency
Normal allele 
Mutant r allele 
Genotype frequency
Homozygous normal bugs 
Homozygous mutant bug 
Heterozygous normal bug with one mutant r allele and one normal allele 
Reactions in which the concentration of Nucleophile or Base has no effect on the rate of reaction depends only on the concentration of substrate. Such reactions are called Unimolecular Substitution or Elimination Reactions. The Kinetics of such reaction is First order with respect to substrate.
Examples:
SN¹ Reactions: These are Unimolecular Substitution reactions. These are two step reactions in which the first step is the rate determining step. In RDS the substrate is ionized to generate a carbocation and is the slowest step. In second step the Nu attacks carbocation and is the fastest step.
E¹ Reactions: These are unimolecular Elimination reactions. These are also two step reaction. In first step carbocation is generated (RDS step) and in second step the base abstracts proton to yield alkene. These reactions only depend on the concentration of substrate.