If you don't have an aerator, you need to change the water very other day at least--but take care not to stress the fish in doing this. The easiest solution is to get a proper aerator.
No. Water is oxygen to them so they need to be in water in the plastic bowl.
you should change it every week so it will always be clean.
1 gallon tanks & smaller need to be changed/cleaned every 5 days.
When you are changing the water in a fish bowl, you have to empty cup ot bowl with water in it. Then, put it into clean water.
When you first change the water in your aquarium , there is lots and lots of waste flowing around in the water from the gravel in the bottom of the tank. it seems that your beta is just getting oxygen from the top of the water. hope this helps
A geckos water bowl should consist of clean water at all times. This means the bowl must be changed and clean every day. In most cases a water bowl will evaporate if a heating lamp is present but if not, that water will turn stale, possibly grow mold and is possible to make your animal ill. The animals habitat should be cleaned monthly at a minimal.
About every 2-3 days. Cats don't need fresh water every day. If you have a water bowl set up outside, then I'd probably change it more often. But in the house, every 2-3 days or when you notice it is getting empty is ok.
physical change
No, They need oxygen in the water to live, and space to swim around.
If your fish are swimming up to the surface and gasping for air it a sure sign that there is not enough oxygen in the tank; another sign may be an increased flaring of the gills. You need to buy a filter for the tank (or if you already have one a stronger filter) in order to more efficiently replenish the oxygen supply. If the 'tank' is a small bowl, change the water more often. You don't take them out of the water.
No. It is a physical change.
Parrots do not deliberately soak their tails in their water bowl. Because there is often a perch next to the water bowl, whenever they turn around while they are sitting there their tail will end up in the water.