Answer:
Concentration, because the amounts of reactants and products remain constant after equilibrium is reached.
Explanation:
The rate of reaction refers to the amount of reactants converted or products formed per unit time.
As the reaction progresses, reactions are converted into products. This continues until equilibrium is attained in a closed system.
When equilibrium is attained, the rate of forward reaction is equal to the rate of reverse reaction, hence the concentration of reactants and products in the system remain fairly constant over time.
When deducing the rate of reaction, concentration of the specie of interest is plotted on the y-axis against time on the x-axis.
Answer: The ion is 
. The chemical symbol of the noble gas this ion is isoelectronic with Kr.
Explanation:
The given electronic configuration is,
The number of electrons = 2 + 2 + 6 + 2 + 6 = 18 electrons
As the ion has a charge of +2 , that means it has lost two electrons so the the neutral element will have 2 more electrons i.e 18+2 = 20. The element has atomic number of 20 and the element will be Calcium with electronic configuration of
Thus the symbol of ion is . the nearest noble gas with 18 electrons is Krypton with symbol Kr.
The charge that 3 protons, 3 neutrons and 2 electrons have is that it will be a cation of Li with a charge of +1.
Li^+1.
