Answer:
A. the jar covers
Explanation:
An independent variable is what you, as the scientist, changes.
Answer:
C. Chemical change
Explanation:
A physical change is where something is changed but it doesnt affect the build up of the chemical. For example, if you broke sticks and threw them on the ground, that would be a physical change because the change is happening to the physical being of the object and not its chemical buildup. However, if you lit those sticks on fire, that would be considered a chemical change because you end up with two substances, ash and the remnants of the stick. A nuclear reaction would result in something blowing up so its not that. And a physical property is like what it looks like or how it smells. Hope I helped you!
NaCl is salt to it is obviously SOLUBLE :)
Answer: 53.25
Explanation: Please see attachment for explanation. Thanks.!
The last one 1) exothermic; 2) exothermic
