Which occurs more often on earth? physical or chemical changes?

Cobalt-60 is an artificial radioisotope that is produced in a nuclear reactor and is used as a gamma-ray source in the treatment of certain types of cancer. if the wavelength of the gamma radiation from a cobalt-60 source is 1.00 × 10-3 nm, calculate the energy of a photon of this radiation.

Which of the following elements would you expect to have the lowest ionization energy value? fluorine, lithium, neon, nitrogen

Which statement best explains the relationship between an area is geography and the temperature of its surface water