Properties of the molecular clump and the associated ultracompact H II region in the gas shell of the expanding H II region Sh 2-104

We study the physical and chemical properties of the molecular clump hosting a young stellar cluster, IRAS 20160+3636, which is believed to have formed via the "collect and collapse" process. Physical parameters of the UC H ii region associated with the embedded cluster are measured from the radio continuum observations. This source is found to be a typical Galactic UC H ii region, with a B0.5 type exciting star, if it is ionized by a single star. We derive a CN/HCN abundance ratio larger than 1 over this region, which may suggest that this clump is being affected by the UV radiation from the H ii region.