Digital F Stop question

I'm been looking at the Nikon D70 and have been surprised at the offered
standard lens, Zoom-Nikkor 18-70mm f/3.5-4.5.

I'm aware of the multiplication factor one must to use to convert the mm to
35 mm camera equivalent because of the sensor size, but is there also some
sort of conversion for f-stops as well?

In other words, assuming ASA-100 for both a 35 mm film camera and the Nikon
D70, would the Nikon f/3.5 lens be as slow as it sounds, and so
inappropriate for low light level photography?

Thanks,
Bruce.