Select the correct answer. Which statement about ecosystems is true? A. ecosystems are always a few square meters at most. B. ecosystems are exactly one square kilometer. C. ecosystems are always larger than a biome D. ecosystems are always smaller than a biome. Plz help​

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?

Imagine that you push on a large rock. at what point does your effort change the rock’s mechanical energy?

Aconcentrated solution of ammonia is 14.8m and has a density of 0.899g/l. what is the concentration of ammonia in this solution in weight percent (%w/w)?