Answer: The rate constant is
Explanation ;
Expression for rate law for first order kinetics is given by:

where,
k = rate constant = ?
t = age of sample = 4.26 min
a = initial amount of the reactant = 2.56 mg
a - x = amount left after decay process = 2.50 mg
Now put all the given values in above equation to calculate the rate constant ,we get



Thus rate constant is [tex]0.334s^{-1}
In order to calculate the final concentration of a dilution, it is important to memorise and remember the following equation:
C1V1/C2V2
Where:
C1 = Initial concentration
V1 = Initial volume
C2 = Final concentration
V2 = Final volume
We are given three of the four, and we are asked to calculate the final concentration in moles, so we may substitute these given values into our equation as follows:
C1V1 = C2V2
(2.00m)(50.0 mL) = (C2)(500mL)
100 = C2(500mL)
C2 = 0.2 m
In the final step, we simply divide 100 by 500 to get our final concentration value.
Answer:
iIllustrated Glossary of Organic Chemistry - Atomic radius. Atomic radius: The radius of an atom. This distance between an atom's nucleus and outer electron shell. ... Atomic radius differs with the bonding state of an atom (for example an nonbonded atom of an element versus the same element within a covalent bond).