Amineral breaks into flat sheets when struck with a rock hammer. which property of a mineral is being measured? a. streak b. cleavage c. hardness d. color

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.

Which electron configuration represents the electrons in an atom of sodium in the ground state at stp

What does the symbol (–hfus) indicate in a phase change?