For the redox reaction Zn(s) + Cu²⁺(0.1 M) $$\to$$ Zn²⁺(1M) + Cu(s) taking place in a cell, $$E_{cell}^o$$ is 1.10 volt. E_cell for the cell will be ($$2.303{{RT} \over F}$$ = 0.0591)

Several blocks of magnesium are fixed to the bottom of a ship to :

The radionucleide $${}_{90}^{234}Th$$ undergoes two successive $$\beta$$ -decays followed by one $$\alpha$$-decay. The atomic number and the mass number respectively of the resulting radionucleide are

The half-life of a radioactive isotope is three hours. If the initial mass of the isotope were 256 g, the mass of it remaining undecayed after 18 hours would be