The answer is Ag.................silver
True. The world population in 1965 was 3.324 billion . In 2000 the world population was 6.115 billion. The difference is 2.791.
The reducing agent is donating electrons and therefore becoming oxidised itself. In this scenario elemental zinc (Zn) is in a reduced state and is oxidised to become Zn2+, in doing so it donates electrons to Fe2+, thereby reducing it to elemental iron (Fe).
The elemental Zinc in solid state is therefore the reducing agent as it reduces Fe2+ to Fe(s).
The electron configuration of lithium atom is:
![Li:[He]2s^1](https://tex.z-dn.net/?f=Li%3A%5BHe%5D2s%5E1)
The number "2" is the value of the principal quantum number "n". Letter "s" is associated with the value of secondary quantum number "l" and it is equal to zero. The value of "m" (or magnetic quantum number) is zero too. The quantum number set for the highest energy electron will be (2, 0, 0, 1/2).