Please answer correctly :))

Name the element in group 17, period 2. (periodic table)

Aperfume bottle is dropped in the corner of a room. the odor of the perfume can be detected on the other side of the room. which statement best describes this observation?

Given the following at 25c calculate delta hf for hcn (g) at 25c. 2nh3 (g) +3o2 (g) + 2ch4 (g) > 2hcn (g) + 6h2o (g) delta h rxn= -870.8 kj. delta hf=-80.3 kj/mol for nh3 (g), -74.6 kj/mol for ch4, and -241.8 kj/mol for h2o (g)