Answer: B
Explanation:
At equilibrium, the rate of the forward reaction is equal to the rate of the reverse reaction, and thus the concentrations of the reactants and products must be constant.
The outer core of the Earth is a fluid layer about 2,300 km (1,400 mi) thick and composed of mostly iron<span> and</span>nickel<span> that lies above Earth's solid inner core and below its mantle. Its outer boundary lies 2,890 km (1,800 mi) beneath Earth's surface.</span>
