2C2H6+7O2=4CO2+6H2O. In the above balanced equation, how many molecules are there of each of the following(hint: convert moles to molecules):
a. C, H.
b. 02

C. CO,
d. H2O

0.09 moles of sodium sulfate in 12 ml of solution

Write the chemical formula for a compound that is made of an element from group 1 and an element from group 17

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.