1. Explain why elements tend to form bonds in compounds and provide two examples of how they can do that. 2. Difference between polar and non-polar molecule.

The idea that all living things are made up of cells is considered scientific law. this means the idea is an emerging scientific idea that has a logical explanation. has been tested with similar results at least twice. is supported by scientific consensus and a large amount of evidence. has been rejected only once by the scientific community