Oxidation number of an atom is the charge that atom would have if the compound is composed of ions. In neutral substances that contains atoms of one element the oxidation number of an atom is zero. Thus atoms in O2, Ni2, and aluminium all have oxidation number of zero.
In this case, Ni2, the oxidation number of Ni atom is zero,
for NiO4-, assuming oxidation number of Ni is x
(x ×1) + (-2 × 4) = -1
x = + 7
Therefore, the oxidation number goes from 0 to +7
Hey there!
A half-life means after a certain amount of time, half of that substance will be gone/changed after that time.
If 50%, or half, of the element remains after 4000 years, that means the half life must be 4000 years.
Hope this helps!
I'd say he ways about 35 kilograms, but I'm probably wrong, xD
