The balanced equation below represents a reaction between propane and oxygen. C3H8 + 5 O2 → 3 CO2 + 4 H2O According to this equation, which ratio of propane to oxygen is correct? 5 grams CO2 1 gram C3H8 3 moles CO2 1 mole C3H8 5 moles O2 1 mole C3H8 3 moles CO2 4 moles H2O

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

Compare and contrast physical changes with chemical changes.

Melting and boiling are endothermic processes. this means that these processes absorb energy from their surroundings in order to occur. use this information and the data you collected in the phase change gizmo to describe what happens to the temperature of water when you boil it, then explain why this result occurs.