How are pandemics different than epidemics? Pandemics affect blood; epidemics affect skin.

Pandemics affect many countries or states; an epidemic is more localized.

Pandemics are caused by bacteria; epidemics are caused by viruses.

Pandemics are spread through the air; epidemics are spread through the water.

Modern weaponry has increased the number of deaths in wars and violent conflicts.

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?

In salt water solution,the salt is the blank