What type of reaction are these?

1) 2 MgI₂ + Mn(SO₃)₂ → 2 MgSO₃ +MnI₄

2) P₄ + 3 O₂ → 2 P₂O₃

3) SeCl₆ + O₂ → SeO₂ + 3 Cl₂

4) C₃H₆O + 4 O₂ → 3 CO₂ + 3 H₂O

Which of the following is the correct definition of chemical energy? a. energy an object has because of its motion or position b. energy resulting from the flow of charged particles, such as electrons or ions c. energy produced from the splitting of atoms d. energy stored in chemical bonds of molecules