Answer:
When you pull a rubber band there is elastic potential energy stored in the rubber band but once you let go of either side the EPE turns into Kinetic Energy.
Answer:
1.71 kJ/mol
Explanation:
The expression for the calculation of the enthalpy change of a process is shown below as:-
Where,
is the enthalpy change
m is the mass
C is the specific heat capacity
is the temperature change
Thus, given that:-
Mass of CaO = 1.045 g
Specific heat = 4.18 J/g°C
So,
Also, 1 J = 0.001 kJ
So,

Also, Molar mass of CaO = 56.0774 g/mol

Thus, Enthalpy change in kJ/mol is:-

<span>The scientific method is a systematic way of questioning about the world around us and answering questions. The number of steps varies from one description to another, mainly when data and analysis are separated into separate step, but this is a fairly standard list of 6 scientific method steps, which you are expected to know for any science class:
1. Form a Hypothesis. This is a sort of educated guess about what you expect.
2. Design an Experiment to test your hypothesis. An experiment has an independent and dependent variable. You change or control the independent variable and record the effect it has on the dependent variable.
3. Conduct Experiment
4. Record data and observations and analyze what the data means. Often, you'll prepare a table or graph of the data.
5. Form a Conclusion. Conclude whether to accept or reject your hypothesis. Communicate your results.</span>
In order to balance an equation, we apply the principle of conservation of mass, which states that mass can neither be created nor destroyed. Therefore, the mass of an element before and after a reaction remains constant. Here, the balanced equation becomes:
4Al + 3O₂ → 2Al₂O₃
The coefficients are 4, 3 and 2.