Assuming the heterocyclic ring above to be planar: Give the number of electrons that are contributed to the pi system of the heterocyclic ring by: atom 1 ___ ; atom 2 ___ ; atom 3 ___ . Enter NA for atom 3 if the structure above has only two numbered atoms. How many electrons are in the pi system of the heterocyclic ring

1)each group 16 element has how many valence electrons? ( )4 ( )6 ( )8 ( )16 2)how many dots appear in the dot structure for calcium ion, ca2+? ( )zero ( )one ( )two ( )eight 3) which of the following atoms forms a cation to obtain an octet of outer shell electrons? ( )magnesium ( )oxygen ( )fluorine ( )helium 4) an al3+ ion contains 13 protons and 10 electrons. ( )true ( )false 5) valence and non-valence electrons are represented in lewis dot structures. ( )true ( )false

Use the measurements in the table to determine which unidentified metal has the highest density. metal volume mass a 10.5 cm3 122 g b 14.2 cm3 132 g c 16.1 cm3 115 g d 12.7 cm3 126 g

Select the correct answer. wax is a nonpolar substance. in which type of substance is it the most soluble?