Answer:
People were unaware about the basic elements which constituted hydrogen and oxygen. and water was everywhere
It is impossible to run 15 miles an hour
I think
Hope this helps :D
Answer:
Halogen / salt-former
Explanation:
Bromine is classified as an element in the 'Halogens' section which can be located in group 7 of the Periodic Table. The term "halogen" means "salt-former" and compounds containing halogens are called "salts".
Answer:
He
Explanation:
From Graham's law of diffusion, lighter or less dense gas tends to diffuse faster than denser gas amongst the list, He is the lightest gas and so will diffuse faster