Nebula Supernova - Crab Nebula. The Crab Nebula represents a violent supernova explosion of a star (likely a third, fourth, or even later generation star). Heavy elements with atomic weights greater than 26 (and some with lesser atomic weights between oxygen and iron) were likely generated during this explosion. Which element probably formed in a supernova?a. Gold (Au) b. Carbon (C) c. Hydrogen (H) d. Helium (He)

Which of the following would not be considered a geographic impact on the history of middle and south america? a. the relative geographic isolation of the americas meant that they would be more susceptible to european diseases. b. ernesto “che” guevara's trip throughout south america inspired him to become a revolutionary. c. the tropical climate of north america has encouraged many south american countries to produce goods there. d. the proximity of the united states to middle and south america has strengthened its relationship to the region.