The gas that living things need to survive is composed to two oxygen atoms covalently bonded to each other (O2). A- humans artificial bond molecules together so we don’t run out of useable oxygen. B- Oxygen does not have a full nucleus of protons, and therefore binds with other molecules to fill each of their nuclei. C- Oxygen is a very sticky element and therefore gets stuck to also other atom floats past. D- Oxygen does not have a full valence electron shell, and therefore binds with other molecules to fill each of their shells. HELPP PLS !

The enthalpy of formation of water is -285.8 kj/mol. what can be inferred from this statement?

Why is carbon ideal for making different compounds?

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.