01Favorable but slow
A reaction can have ΔG < 0 and still not happen noticeably because its activation energy is huge. That's kinetic control.
Diamond → graphite is favorable but takes forever. Paper doesn't spontaneously burn at room temperature.
02Notebook box
ΔG says whether; Ea says how fast.
Worked example: Why doesn't a mixture of H₂ and O₂ explode until sparked? Large Ea; the spark supplies it.