Which of the below substances is a radioactive gas caused by the decay of uranium?
Radon
Mercury
Carbon Monoxide
Lead
Ultraviolet (UV) Rays

Adnexa is a word that literally means and is applied chiefly to refer to the appendages of the eye. an antrum is a _sinuscavity_, especially within a bone. the term asthenopia means a condition of in the an astrocytoma is a consisting of hypercrinia refers to of any endocrine gland. dacryogenic pertains to the of dura means and is used as a shortened form or duramater, the outer covering of the brain. the word fascia is used to denote a of fibrous tissue. heliosensitivity denotes to the hypnology is the of the term isocellular refers to the composition of cells of the size or kind. a laparogastrostomy is the creation of a permanent to the through the wall. the term malignant is used to mean something demetia is a general term for deterioration. the term oculopathy refers to any of the prepartak means occurring just the term podalic denotes being accomplished by means of the a mastoscirrhus is a cancer of the sclerosis is a of a septum is a general term to designate a dividing a sinus is a in the body the term somatopathy denotes a as distinguished from a mental one. tarsus pertains to the region of the foot. the term topalgia denotes trachelomyitis is an of the within the