It <span>Ions were once atoms with the same number of electrons and protons. Since they have opposite charges atoms are neutral. When they become ions the lose or gain electrons and become unbalanced. ... These different charges are attracted to each other via electric forces.</span>
For a standing wave on a string, the wavelength is equal to twice the length of the string:

In our problem, L=50.0 cm=0.50 m, therefore the wavelength of the wave is

And the speed of the wave is given by the product between the frequency and the wavelength of the wave: