Is cutting a paper snowflake a chemical or physical change and why?

In a sample of oxygen gas at room temperature, the average kinetic energy of all the balls stays constant. which postulate of kinetic molecular theory best explains how this is possible?

H2so4(aq) + mg(s)—> mgso4(aq) +h2(g) which substance is the acid in the reaction?

If you have 5.25 grams of methane (ch4), how many grams of co2 will you produce ?