One gallon of gasoline in an automobiles engine produces on average 9.50 kg of carbon dioxide, which is a greenhouse gas; that is, it promotes the warming of Earth's atmosphere. Calculate the
annual production of carbon dioxide in kilograms if there are exactly 40.0 million cars in the United
States and each car covers a distance of 6950 mi at a consumption rate of 19.0 miles per gallon. Enter
your answer in scientific notation.

How many moles of air are there in a human lung with a volume of 2.4 l at stp? explain your answer

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.

Element before carbon on the periodic table