Ahydrologist from a government agency tests several samples of water for safety. as part of his examinations, he determines the concentration of lead that is
present in each sample.
which method of expressing concentration should the hydrologist use to describe the concentration of lead in the water?
mass percent
ppm or ppb
volume percent
mass-volume percent

Identify two factors that determine the rate of stream erosion

How does the amount of energy required to hold each proton and neutron in the nucleus compare to the energy released when they are removed?

Assume that two of the electrons at the negative terminal have attached themselves to a nearby neutral atom. there is now a negative ion with a charge -2e at this terminal. what are the electric potential and electric potential energy of the negative ion relative to the electron? the electric potential and the electric potential energy are both twice as much. the electric potential is twice as much and the electric potential energy is the same. the electric potential is the same and the electric potential energy is twice as much. the electric potential and the electric potential energy are both the same. the electric potential is the same and the electric potential energy is increased by the mass ratio of the oxygen ion to the electron. the electric potential is twice as much and the electric potential energy is increased by the mass ratio of the oxygen ion to the electron.