How many grams of NaHCO3 must be added to 4.0g of K2CO3 to give a pH of 10.80 in 500mL of water?

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.

Draw two cyclic constitutional isomers of cis-1

Select the word from the list that best fits the definition the nuclear family into which a person is born or adopted.