Which Of The Following Is The Simplest Form Of Substance. A hydrogen atom which is a proton with an orbiting electron would be next next simplest which is technically called protium. Which choices best describes a reasonable mechanism for animal structures becoming better suited over evolutionary time to specific functions.

It is the simplest form of matter. A substance that contains two or more elements chemically combined in a fixed proportion. Comb jellies have a sticky substance on their tentacles to trap prey.
Which is the best example of a pure substance.
Simple Substance a homogeneous substance composed of the atoms of a chemical element. Which of the following would indicate that a new substance has formed. Jellyfish have nematocysts to sting and immobilize prey. Which of the following is a substance.