¿ en que consiste la ley de la conservación de la materia y como se utiliza en la quimica ?

Define dew point. i am writing this part to be able to ask the question

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

Which of the following is most likely true about water in chemical solutions?