What is the empirical formula of if the molecular formula is
C2H2O4

Agas diffuses 1/7 times faster than hydrogen gas (h2). what is the molar mass of the gas? 100.10 g/mol 98.78 g/mol 86.68 g/mol 79.98 g/mol

Avariable that is not being directly tested during an experiment should be

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.