Which statement best describes how a catalyst increases the rate of a reaction?
(1) the catalyst provides an alternate reaction pathway with a higher activation energy.
(2) the catalyst provides an alternate reaction pathway with a lower activation energy.
(3) the catalyst provides the same reaction pathway with a higher activation energy.
(4) the catalyst provides the same reaction pathway with a lower activation energy.

Given sno2 + 2h2 - sn + 2h20 tin oxide reacts with hydrogen to produce tin and water. how many moles of sno2 are needed to produce 500.0 grams of sn?

Compare and contrast refraction of light and sound will give brainliest

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.