Which is true of any physical or chemical reaction? *?

An occluded front moves over the farmland that has been experiencing drought conditions. what change in weather will this front likely bring? a. gray skies, but no rain b. an extended period of rain c. more dry air and sunny skies d. violent, short-lived thunderstorms

18. use the activity series to predict whether the following synthesis reaction will occur. write the chemical equations for the reaction if it's predicted to occur. (s) + o2(g) -> *note: it is possible.*

What is the temperature of one mole of helium gas at stp?