What is the mole ratio of oxygen to pentane

Which compound contains both ionic and covalent bonds? a) hbr b)cbr4 c)nabr d) naoh

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

The number of neutrons is equal to the atomic number minus the atomic mass. a. true b. false