1. Communicate Explain how you would calculate the wavelength of a wave if you knew both the wave's speed and frequency.
Type your answevere

Yes it would be a physical change.

Ithink about 50 % of an original isotope's number of atoms remain

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