WHAT ARE FUSION AND FISSION? HOW IS A NUCLEAR REACTION CONTROLLED? RADIOACTIVITYFIND OUT MOREThe energy that makes the stars shine and produces the heat inside a nuclear reactor is nuclear energy.…
Was Three Company? Past evidence uncovered in Israel and France has shown that Neanderthals lived on Earth at the same time as modern Homo sapiens. Neanderthals were found to have lived about 34,…
What causes a rainbow? A rainbow in Indiana, Oct. 2015. Source: AP Photo/Michael Conroy Although light looks colorless, it’s made up of many colors-red, orange, yellow, green, blue…
(Encyclopedia) International Geophysical Year (IGY), 18-month period from July, 1957, through Dec., 1958, during a period of maximum sunspot activity, designated for cooperative study of the solar-…
(Encyclopedia) muckrakers, name applied to American journalists, novelists, and critics who in the first decade of the 20th cent. attempted to expose the abuses of business and the corruption in…
(Encyclopedia) star cluster, a group of stars near each other in space and resembling each other in certain characteristics that suggest a common origin for the group. Stars in the same cluster move…
(Encyclopedia) technetiumtechnetiumtĕknēˈshēəm [key] [Gr. technetos=artificial], artificially produced radioactive chemical element; symbol Tc; at. no. 43; mass no. of most stable isotope 98; m.p. 2,…
(Encyclopedia) bariumbariumbârˈēəm [key] [Gr.,=heavy], metallic chemical element; symbol Ba; at. no. 56; at. wt. 137.327; m.p. 725℃; b.p. 1,640℃; sp. gr. 3.5 at 20℃; valence +2. Barium is a soft,…
