The temperature cannot be determined by looking at the spectra of the star due to lack of the equipment for its measurement. <em>On the other-hand, the remaining statements like the distance from earth, movement towards or away from earth can be determined.</em>
The answer is 10-12. The relationship of pH and [H+] is pH = -lg[H+]. And the higher pH, the stronger base is. So the strongest base has the lowest concentration of H+.
