Which radiation causes cancer? I think it is UV radiation, but I'm not sure.

Also,
A wave goes up and down 5 times in 10 seconds. what is the frequency of the wave in cycles per second (Hertz)

1 answer

Ultraviolet waves shorter than about 350 nm can cause skin cancer.

Frequency (in Hz) equals 1/Period, and in this case the period is 2 seconds.