C. Which reactions is endothermic and which one is
exothermic? How do you know?

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.

Plz ill give u brainliest which of the following steps is not likely to take place during cellular respiration? a. oxygen combines with carbon of simple sugar. b. energy molecule transfers energy to cells. d. energy is used up.

What is the chemical equation of fire?