In 1865 a pond was surrounded by open fields today the same area is swampy and surrounded by a forest which process is responsible for this change?

There are 6.022 x 10^23 atoms of hg in 1 mole of hg. the number of atoms in 4.5 moles of hg can be found by multiplying 4.5 by 6.022 x 10^23 a. 2.7 x 10^24 b. 27 x 10^23 c. 2.71 x10^24 d. 27.099 x 10^23

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?

How have the greenhouse gasses increased from the year 2000 to 2018