The heliocentric theory explains that planets orbit the Sun at the center of our solar system. It replaced the geocentric theory, which suggested that all objects in space orbit Earth. Which evidence could have helped disprove the geocentric theory and lead to development of heliocentric theory? A. Objects in sky, including Sun, appear to revolve around Earth on a daily cycle. B. The planet Earth appears to be a stationary point in space. C. The moons of Jupiter are observed revolving around Jupiter. D. Earth's moon appears larger in the sky than the Sun

answer:

convection currents in the magma drive plate tectonics. heat generated from the radioactive decay of elements deep in the interior of the earth creates magma (molten rock) in the aesthenosphere. the aesthenosphere (70 ~ 250 km) is part of the mantle, the middle sphere of the earth that extends to 2900 km.

oxygen is the first element in group 16 (via) of the periodic table. the periodic table is a chart that shows how chemical elements are related to each other. the elements in group 16 are said to belong to the chalcogen family. other elements in this group include  sulfur, selenium, tellurium,  and  polonium.  the name chalcogen comes from the greek word  chalkos,  meaning "ore." the first two members of the family, oxygen and sulfur, are found in most ores.

oxygen is by far the most abundant element in the earth's crust. nearly half of all the atoms in the earth are oxygen atoms. oxygen also makes up about one-fifth of the earth's atmosphere. nearly 90 percent of the weight of the oceans is due to oxygen. in addition, oxygen is thought to be the third most abundant element in the universe and in the solar system.