If atmospheric pressure on a certain day is 749 mmhg, what is the partial pressure of nitrogen, given that nitrogen is about 78% of the atmosphere? 165 mm hg 760 mm hg 600 mm hg 584 mm hg 749 mm hg

Which element has the lowest electronegativity? calcium(ca) gallium(ga) selenium(se) bromine(br)

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.

Under which circumstances are kp and kc equal for the reaction aa(g)+bb(g)⇌cc(g)+dd(g)?