The correct order of the atomic radii of C, Cs, Al, and S is :

For the cell Zn(s) |Zn²⁺ (aq)| |M^x+ (aq)| M(s), different half cells and their standard electrode potentials are given below :

Mx+ (aq)/M(s)	Au3+(aq)/Au(s)	Ag+(aq)/Ag(s)	Fe3+(aq)/Fe2+ (aq)	Fe2+(aq)/Fe(s)
E0Mx+/M/(V)	1.40	0.80	0.77	$$-$$0.44

If $$E_{z{n^{2 + }}/zn}^0$$ = $$-$$ 0.76 V, which cathode will give maximum value of E^o_cell per electron transferred?

The element that usually does NOT show variable oxidation states is :

Heat treatment of muscular pain involves radiation of wavelength of about 900 nm. Which spectral line of H atom is suitable for this purpose?

[R_H = 1 $$ \times $$ 10⁵ cm^–1, h = 6.6 $$ \times $$ 10^–34 Js, c = 3 $$ \times $$ 10⁸ ms^–1]