Explanation:
Balanced chemical reaction equation will be as follows.

In human body, the neutral iron changes into
(aq) cation. There will be an oxidation-half reaction and a reduction-half reaction. Equations for this reaction are as follows.
Oxidation: 2Fe^{2+}(aq) \rightleftharpoons 2Fe^{3+}(aq) + 2e^{-}[/tex] .... (1)
Reduction:
...... (2)
On adding both equation (1) and (2), the overall reaction equation will be as follows.

Therefore, neutral iron is a part of Heme - b group of Hemoglobin and in an aqueous solution it dissolutes as a part of Heme group. Hence, then it becomes an
cation.
Answer:
HBrO4 < HBrO3 < HBrO2 < HBrO
Wavelength of the light is 2.9 × 10⁻⁷ m.
<u>Explanation:</u>
Planck - Einstein equation shows the relationship between the energy of a photon and its frequency, and they are directly proportional to each other and it is given by the equation as E = hν,
where E is the energy of the photon
h is the Planck's constant = 6.626 × 10⁻³⁴ J s
ν is the frequency
From the above equation, we can find the frequency by rearranging the equation as,
ν =
= 
Now the frequency and the wavelength are in inverse relationship with each other.
ν × λ = c
It can be rearranged to get λ as,
λ = c / ν
= 
So wavelength is 2.9 × 10⁻⁷ m.