Is the amount of gas in the tube (in terms molar mass) a variable or constant

What must occur for air masses to form fronts

Nan element’s square on the periodic table, the number with the greatest numerical value represents the

What do electromagnetic waves carry? how are they produced through which media can they move? where do they transfer energy? what do they not transfer? what do mechanical waves carry? how are they produced? through which media can they move? where do they transfer energy? what do they not transfer?