During a recent winter month in sheboygan, wisconsin, it was neccessary to obtain 3500 kwh of heat providd by a natural gas furnace with 98 % efficiency to keep a small house warm (the effiiency of a gas furnace is the percent of the heat produced by combution that is transferred into the house).
(e) what volumem of air is required to provide the oxygen for the combustion of the methane used to heat the house ? air contiais 23% oxygen by mass. the average density of air during the month was 1.22g/l.

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.

a saline water is fed to a reverse osmosis unit at flow rate o rotameter connected to reject (retentate) line reads 8 installed in reject and permeate line reads 15.2 milli siemens/cm and 300 micro siemens/com respectively.

they vary. it used to be meat, grain, bread, candy, beverages, donuts, and fruits/vegetables. now they added exercise in.