Answer and Explanation:
First, observe and understand what is happening.
1. A balloon is on an empty glass bottle, which is placed in water that is being heated.
2. The balloon starts to become inflated, or filled with air.
5. The balloon gets inflated because:
(B) The air inside the bottle gets heated and expands.
The bottle is already filled with air (due to it being exposed before putting the balloon on it to cover the bottle). When air is heated, the molecules start to move around rapidly, coming into contact very frequently and wildly, which makes the air expand into the balloon, ultimately inflating it.
6. What do you expect if the bottle is taken out?
(A) The balloon will get deflated.
Due to the air in the bottle no longer being heated, the molecules will start to slow down, and the balloon will deflate.
7. The changes taking place in the balloon when the bottle is placed in the hot water and taken out of it are:
(A) Reversible
Although heat is used in the process, the air itself isn't changed chemically, only physically. The air can go from being at normal temperature to hot to being hot and back to normal temperature. Even if you were to freeze the air/make the air cold, the air can change back to normal temperature when heating the air.
1. When you put some glucose in your mouth, your tongue feels cold, because the dissolving of glucose in saliva is an endothermic change.
Endothermic reactions are where the reactants absorb the heat from the surrounding area to form the product. The glucose absorbs the warmth from your tongue, and as a result you feel the coldness of the glucose.
#teamtrees #PAW (Plant And Water)
I hope this helps!
