If an atom gains some extra electrons so that its valence shell becomes full, what happens to the atom?
a. it becomes less stable.
b. it becomes more stable.
c. its charge becomes neutral.
d. nothing. it just has more electrons now.

What is the chemical formula of the following compound

If you have 5.25 grams of methane (ch4), how many grams of co2 will you produce ?

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.