Aimportância das plantas para os humanos

If 1.63 times 10 negative 4 of helium dissolves in 100.0g of water, what is the concentration in parts per million

An alloy contains 66 g of pure zinc. what is the percentage of zinc in the alloy? express your answer to two significant figures and include the appropriate units.

What type of electromagnetic waves does the human eye see as the colors red blue or green a visible light waves b radio waves c infrared waves d microwaves