HI dissociates to form 12 and Hz: 2HI(g) → H2(g) + 12(9) If the concentration of Hl changes at a rate of -0.45 mol L's? what is the rate of appearance of 12(g)?

Perform the following mathematical operations and report the answer to the appropriate number of significant figures 5.87998 + 3.100

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

Asample of sea water contains 6.28g of sodium chloride per litre of solution. how many milligrams of sodium chloride would be contained in 15.0ml of this solution?