Can someone explain what is the wave length for extremely low frequency radiation (ELF) and television waves.

Can someone explain what is the wave length for extremely low frequency radiation (ELF) and television waves. Please show how to work them out. thanks

Determine the activity (in Bq) of the radioactive material.

A device used in radiation therapy for cancer contains 2.2 g of cobalt-60 (59.933 819 u). The half-life of this isotope is 5.27 yr. Determine the activity (in Bq) of the radioactive material. Number :-___________________ Units:____________________