Sweating.
Sodium and Chloride
"Deutronium"
mineral ions are mainly lost when you exercise (run) or get too hot. This causes your body to go into intant unconious cool down which means you sweat. Sweat is water particles (mineral ions) so when our bodies get rid of it, you're loosing water/mineral ions. This also means that you should top up your intake of water as you dont want to sweat too much that you loose it all.
1. Through sweating 2. Through increased breathing
Yes: it is fluid lost through sweating.
Some water is lost through exhaled air, more is lost through sweating. Either way it can get you dehydrated.
Potassium
Sweating too much will not kill but it will cause dehydration that may kill if not enough water is being replenished. Heavy sweating can cause major social and personal problems to your life. If you are sweating alot for no particular reasons, you may be suffering from a medical problem termed hyperhidrosis (excessive sweating)
Not really. While in there, you'll sweat. The water lost through sweating will indeed lose you some weight. Trouble is, sweating makes you thirsty. And as soon as you satisfy your thirst by drinking, that weight lost through sweating is right back onboard.
Water is lost from sweating, Urination, breathing through evaporation and excretion of waste from diarhea.
Some is lost through breathing, some through sweating and the rest through toilet visits.