Properties of elements within a blank on the periodic table change in a predicatable way from one side of the table to the other

Which compounds have the empirical formula ch2o? a.c2h4o2 b.c3h6o3 c.ch2o2 d.c5h10o5 e.c6h12o6

Acontrol during an experiment. might change remains constant does not exist does change

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