A sound wave with a wavelength of 2.5 M travel 660 immature seconds calculate the frequency of the wave

What does the start look like

The chemical reactions lab we did is typically called a "copper plating lab,  because the acid solution cleaned the pennies and made the copper look shinier;   the acid solution cleaned the paperclips and made them look like pennies;   &   the copper from the pennies was removed, and then added to the paperclips. 

The answer is d, you can easily test a theory! hope i you : )