Identify any combination reactions. (Select all that apply.)
a. HgO → Hg + O₂
b. Ga + H₂SO₄ → Ga₂(SO₄)₃ + H₂
c. C₄H₁₀ + O₂ → CO₂ + H₂O
d. K + Br₂ → KBr
e. AgCl₂ + H₂ → Ag+HCl
f. NaNO₃ → NaNO₂ + O₂
g. Noene of these