  We consider influence of finite size of ions on properties of classic
plasmas. We focus our attention on the ion sound for electron-ion plasmas. We
also consider dusty plasmas, where we account finite size of ions and particles
of dust and consider the dispersion of dust acoustic waves. Finite size of
particles affects classical plasma properties. Finite size of particles gives
considerable contribution for small wave lengths, which is area of appearing of
quantum effects. Consequently, it is very important to consider finite size of
ions in quantum plasmas as well.
