Explain why changes of state are physical changes.

9. write the chemical equation for the following word equations. include symbols for physical states in the equation. a. solid zinc sulfide + oxygen gas -> solid zinc oxide + sulfur dioxide gas b. aqueous hydrochloric acid + aqueous barium hydroxide -> aqueous barium chloride + water

What mass of natural gas (ch4) must you burn to emit 276 kj of heat?

Consider the story you just read. all but one of the choices below indicate that something is living.