Beginning with hydrogen how do the chemical elements form?

Problem page gaseous ethane reacts with gaseous oxygen gas to produce gaseous carbon dioxide and gaseous water . if of water is produced from the reaction of of ethane and of oxygen gas, calculate the percent yield of water. be sure your answer has the correct number of significant digits in it.

Answer asap : ( a. how does mucus prevent the entry of pathogens? b. describe two ways white blood cells protect us from pathogens.

Astring vibrates with a frequency of 10 hz. why can't a person hear the sound waves produced by the vibrating string, no matter how large the amplitude of the waves? out! this is homework and due tomorrow! you so much!