Answer:
A law is a proven fact that can not be changed.
Explanation:
Scienctists are most inquisitive in their research and as such they developed what is called scientific method which they use to create and learn new things. The scientific method includes:
1. Observation.
2. Hypothesis.
3. Experiment
4. Conclusion.
5. Law.
Among this scientific method, the law is the last in the pattern. A law is only given after the experiment has been tested over and over again and found to be true.
Yes i believe there are energy changes when substances are dissolved in water which are either exothermic or endothermic. When a substance is dissolved in water and temperature goes up, heat is released or produced which is called exothermic change. Most substances dissolve in water lowering the temperature and are endothermic changes as energy is absorbed. For example when sodium chloride dissolves in water there is very little change in temperature which is exothermic.
Answer:
129 units cubed
Explanation:
There are ten spaces between 120 and 130, so we can infer that each line represents a change in volume of 1 unit. The volume of the substance in the graduated cylinder looks like it's 1 under 130, so its volume is 129 units.
Hopefully this was helpful! :)
Answer:
B
Explanation:
You add them all together if I'm correct. (I'm in middle school so don't get mad if its wrong lol)
Answers:
a) 10155 J
b) 16.6 J
Explanation:
According to the First Law of Thermodynamics we have:
Where:
is the total change in the internal energy of a system
is the heat exchanged between the system and its surroundings
is the work done on the system
a) In this case 
and 
, hence:
b) In this case 
and 
, hence:
