Answer: 28.231 seconds
Explanation:

Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.
![Rate=k[A]^1[B]^0](https://tex.z-dn.net/?f=Rate%3Dk%5BA%5D%5E1%5BB%5D%5E0)
Thus overall order = 1
Expression for rate law for first order kinetics is given by:

where,
k = rate constant =
t = time taken for decomposition
a = initial amount of the reactant A =
a - x = amount left after decay process = 0.300 M


28.231 seconds will elapse before the concentration of A has fallen to 0.300 mol/liter
The main structural differences between plant and animal cells are the additional structures found in plant cells. These structures include: chloroplasts, the cell wall, and vacuoles.
My Answer: (Ar) 3d10 4s2 4p5
Hope I helped! :D