Answer:

Explanation:
By ideal gas equation law we know that
PV = nRT
now we know that when balloon rises to certain level then the number of moles will remains same
so we can say


now plug in all data to find the final volume of the balloon



The element of a valid contract which is established by getting the signatures of all parties is <u>mutual agreement</u>
<h3>What is an element of a valid contract?</h3>
An element of a valid contract simply refers to that promise made between two or more parties that which allow the courts to make judgement.
Some elements of valid contract are:
- Offer
- Acceptance
- Consideration
- Intention to create legal relation
- Certainty and capacity.
So therefore, the element of a valid contract which is established by getting the signatures of all parties is mutual agreement
Learn more about elements of a valid contract:
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