When silicon-27 is bombarded with a neutron, a gamma ray is emitted. What radioactive isotope is produced?
O aluminum-27
O silicon-28
O silicon-27
O magnesium-27

Oil rich countries in the middle east cover about 4% of earths total land area but prossess about 48% of the worlds known oil reserves what is the main reason for high concentration of reserves in this part of the world