How does a catalyst influence a chemical reaction. A. It speeds up or slows down a chemical reaction by direct participation.
B. it reacts with products to increase the concentration of reactants.
C. It provides an alternative energy pathway for the reaction to proceed.
It provides an alternative energy pathway for the reaction to proceed.
D. It increases the total amount of product formed.

Which fact represents evidence for the big bang theory?

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.

Chemistry worksheet - i am not sure what they are asking for exactly?