The Safe Drinking Water Act (SOWA) sets a limit for mercury-a toxin to the central nervous system - at 0.0020 ppm by mass. Water suppliers must periodically test their water to ensure that mercury levels do not exceed this limit. Suppose water becomes contaminated with mercury at twice the legal limit (0.0040 ppm). How much of this water would a person have to consume to ingest 50.0 mg of mercury?

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?

Which of the following units is not an official si unit

The ozone molecule o3 has a permanent dipole moment of 1.8×10−30 cm. although the molecule is very slightly bent-which is why it has a dipole moment-it can be modeled as a uniform rod of length 2.5×10−10 m with the dipole moment perpendicular to the axis of the rod. suppose an ozone molecule is in a 8000 n/c uniform electric field. in equilibrium, the dipole moment is aligned with the electric field. but if the molecule is rotated by a small angle and released, it will oscillate back and forth in simple harmonic motion. what is the frequency f of oscillation?