What is the activation energy of this reaction?

50 kJ
100 kJ
150 kJ
200 kJ

What is limiting reactant? with examples

Which ocean zone has the most abundant primary producer and why a) the abyssopelagic zone ,du to the absence of light and cold water temperatureb) the bathypelagic zone, due to the absence of light and cold water temperaturec) the mesopelagic zone ,due to uts high light availability and warm water temperature d) the epipelagic zone,due to its high light availability and warm water temperature

Why is the melting of ice a physical change ?