The chemical bonds in CH4 are all single bonds. C only can bond 4 times because it needs 8 electrons in it's outer shell and only has four right now. The bonds represented are all single bonds because there are two electrons present on each side of the carbon. Two electrons, in this case, equals one bond.
Refraction is the bending of light (it also happens with sound, water and other waves) as it passes from one transparent substance into another. This bending by refraction makes it possible for us to have lenses, magnifying glasses, prisms and rainbows. Even our eyes depend upon this bending of light. Hope this helps!
Answer:
The missing information or their role in the discovery of the cell is as follows:
Robert Hooke: He was the first scientist to called cells to tiny box-like cavities he saw in cork and illustrated as cells.
A. Leeuwenhoek: he was a microscopist and microbiologist who used microscopes and observed many other living cells. He called animalcules to these single-cell living organisms later used to prove that cells are the fundamental unit of life.
Schwann and Schleiden: They presented the theory that suggested that the cells are basic building blocks of all living things.
Virchow: He observed that the cell dividing and come from pre-existing cells.
B. Copper since the rest of the choices are compounds. Copper is an element.
the answer is A. I (iodine)
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