Which of the following is correctly balanced? 1) H2 + 202 > 2H20
2) 8C + 2S8 —-> 8CS2
3) 2Na + Cl2 > 2NaCl
4) N2 + 3H2 > NH3

In order to calculate the amount of heat transferred you must know the __ and specific heat of the material, as well as the change in temperature. a. volume b. density c. mass d. enthalpy

Can someone me with these questions plz.

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