Is disobeying a female teacher or professor—such as when one opens a mobile phone after being forbidden from doing so, whether out of necessity or for entertainment—considered unlawful, even though the act itself is not prohibited and no promise was made not to do it?

One must appreciate and respect the school, especially if it comprises people of knowledge and the Qur'an, due to the narrations that encourage honoring the elder and the scholar. Ibn Jama'ah mentioned the manners of a student with his teacher, which include sitting respectfully, listening attentively, refraining from looking away or fidgeting, lowering one's voice, not speaking excessively unless necessary, and avoiding anything that compromises decorum and respect. These manners are among the greatest means of benefit. However, not adhering to them does not incur a religious sin unless it results in significant harm. Opening one's mobile phone to check the time is not a sin. As for receiving a call from a parent, one must seek permission and leave the classroom. A student's disagreement with the teacher on some issues that have a valid basis is not considered bad manners, provided that constant deference is maintained.