The first quantum number identifies the principal energy level of an
electron. True or false

Answer:             1.0  × 10⁻⁵ msolution:                     as we know ph is given as,                                    ph  = -log [h⁺]and,                                    [h⁺]  =  10^-ph    (1)putting value of ph in eq. 1,                                    [h⁺]  =  10⁻⁵                                    [h⁺]  =  1.0  × 10⁻⁵ m

Moles = mass/molar mass by this formula 458/207+32 you should get your answer the ans. is 1.916 mol to 4 sig. fig.

Melting increases as mass increases. since alkanes are not branched molecular structures, the one with the heavier mass will have higher melting point.  octane's mp > butane's mp