Viruses cause most cases of pneumonia in preschool-aged children (i.e., four months to five years of age).1, 9, 16, 24 Although most physicians start antibiotic therapy, guidelines allow for withholding treatment if a viral etiology is suspected and close follow-up can be ensured.1, 9, 13, 15, 16, 24 These children usually have associated symptoms of viral infection, such as pharyngitis, rhinorrhea, and diarrhea .1
Backgrounder on Plutonium. Printable Version. Plutonium is a radioactive metallic element with the atomic number 94. It was discovered in 1940 by scientists studying how to split atoms to make atomic bombs. Plutonium is created in a reactor when uranium atoms absorb neutrons.Nearly all plutonium is man-made.rintable Version. Plutonium is a radioactive metallic element with the atomic number 94. It was discovered in 1940 by scientists studying how to split atoms to make atomic bombs. Plutonium is created in a reactor when uranium atoms absorb neutrons. Nearly all plutonium is man-made.
a chemical element whose isotopes are all radioactive. The class of radioactive elements ineludes. technetium (atomic number 43), promethium (61), polonium (84), and all the elements that follow it in the Mendeleev periodic system (see Figure 1).By 1975, 25 radioactive elements were known.adioactive Element. a chemical element whose isotopes are all radioactive. The class of radioactive elements ineludes. technetium (atomic number 43), promethium (61), polonium (84), and all the elements that follow it in the Mendeleev periodic system (see Figure 1). By 1975, 25 radioactive elements were known.