Read the excerpt from "Thomas Edison: The Master of Improvement.” Its glow was produced by electricity passing through a filament, or tiny piece of material. The inside of the glass bulb was a vacuum. Based on context clues, what is the meaning of the word filament?

Compare and contrast physical changes with chemical changes.

Fill in the coefficients that will balance the following reaction: a0cr2(so4)3 + a1agno3

Which statement is usually true about the relationship between activation energy and reaction rates? low activation energy barriers result in low rates. high activation energy barriers result in low rates. low activation energy barriers result in no reaction. high activation energy barriers result in no reaction.