1-It has to be 3 Fe and not Fe3.
2-The oxygens aren't balanced
Balanced equation:
3Fe+4H2O---->Fe3O4+4H2
A mutation that gives a rabbit a third ear
It takes 33.4 s for the concentration of A to fall to one-fourth of its original value.
A <em>half-life</em> is the time it takes for the concentration to fall to half its original value.
Assume the initial concentration is 1.00 mol/L. Then,

The concentration drops to one-fourth of its initial value in two half-lives.
∴ Time = 2 × 16.7 s = 33.4 s
Answer: b
Explanation: the pressure from gravity in the inner core prevents the iron from melting to a liquid