The system is said to be in dynamic equilibrium when:
select one:
a. there is no longer any net change in the concentrations of products or reactants.
b. the forward and reverse reactions come to a halt.
c. none of these
d. the sum of the concentrations of the reactants is equal to the sum of the concentrations of the products.
e. you have let the reaction proceed for approximately 30 minutes and can assume there will be no more changes.

a) there is no longer any net change in the concentration of products and reactants

Explanation:

There is dynamic equilibrium when in a reversivble reaction stop changing your reagents / product ratio; but the substances move at an equal rate;   System properties do not change over time.

The system is in dynamic equlibrium if it has all three types of equilibrium:

in the analysis of systems that involve fluid flow, we frequently encounter the combination of properties u and pv.

atomic mass = 39

number of neutrons = 20

number of protons= 19

electronic configuration = 1s2 2s2 2p6 3s2 3p6 4s1

the number of electron in first shell = 2

number of electrons in n=3 shell = 8