Me with all the questions and needs to be right u

Write the symbol for every chemical element that has atomic number greater than 3 and atomic mass less than 12.0 u.

What is the volume of the fluid in the graduated cylinder with accuracy and measured to the correct degree of precision? 41.2 ml 42.0 ml 41.23 ml 41.89 ml

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