Answer:
3
Explanation:
It is based on empirical evidence
C.
D.
E.
These should be the main reasons. As Pluto was mainly categorized in dwarf planet for not being able to satisfy the last statement which states that it should have a fixed neighbourhood with other planets.
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}