What mass of natural gas (ch4) must you burn to emit 273 kj of heat

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

Plz choose one of the compounds from the table and explain how you know the numbers of atoms in your formula. is it possible for two different compounds to be made from the exact same two elements? why or why not? with a limited number of elements (less than 120 are known), does this mean we also have a small number of compounds or do we have a large number of compounds in this world?

Which of these features are formed when hot groundwater is forced out through cracks in the earth's surface?