Endurance athletes who exercise for long periods of time and consume only water may experience a sodium deficit in their extracellular fluid. this electrolyte imbalance is known as:

bc blah

explanation:

bc blah

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds