How many moles of helium would occupy a volume of 1.255 L at a pressure of 1.47 atm at a temperature of 21℃?

Which term best describes the form sound takes as it travels away from a drum (a- gas)(b-music) ( c-waves) (d-particles

Which compound contains both ionic and covalent bonds? a) hbr b)cbr4 c)nabr d) naoh

Which statement is true about a catalyst? a: a catalyst decreases the rate of the reaction. b. a catalyst is consumed during a chemical reaction. c. a catalyst lowers the activation energy of a reaction. d. a catalyst increases the reactant concentration during a reaction.