Which item is made from a synthetic material?

Why should the scientific method be used to answer a question? a. it provides a way to test an idea without any bias. b. it provides a way to test a hypothesis. c. it provides a way to ensure all hypotheses are proven correct. d. it provides a way to quickly turn a hypothesis into a scientific theory.

If you chip a tooth, most likely you will go to the dentist to have the missing material filled in. currently the material used to fill in teeth is a polymer that is flexible when put in, yet is hardened to the strength of a tooth after irradiation with blue light at a wavelength of 461 nm. what is the energy in joules for a photon of light at this wavelength?

Stage in which a star’s outer layers have started to cool and grow outward?