An internal combustion engine relies primarily on the efficient production of energy by the combination of oxygen (02) and gasoline (assume this is primarily octane, c8h18). write the chemical equation for this reaction and derive the exact ratio of oxygen to octane for 100% efficiency.

How many atoms are there in 5.70 mol of mg

Match the mixture with the substance// i really need on this guys (it’s a pic btw)

Nebulae are enormous clouds in outer space. they are made mostly of hydrogen gas, helium gas, and dust. some nebulae glow brightly, while others do not. the stars that people see are huge, bright balls of glowing gas. they are made mostly of hydrogen and helium. which statement correctly describes other ways in which nebulae and stars are different? a. stars can form inside a nebula but a nebula can never be produced by any star. b. a star always has a higher density than a nebula. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star.