Is there any specific prompt for the Personal Statement?

No, not exactly. The Common App proposes the following topics and any of them are fine (including a "Topic of your choice"):

• Discuss some issue of personal, local, national, or international concern and its importance to you.
• Indicate a person who has had a significant influence on you, and describe that influence.
• Describe a character in fiction, a historical figure, or a creative work (as in art, music, science, etc.) that has had an influence on you, and explain that influence.
• A range of academic interests, personal perspectives, and life experiences adds much to the educational mix. Given your personal background, describe an experience that illustrates what you would bring to the diversity in a college community, or an encounter that demonstrated the importance of diversity to you.
• Topic of your choice.

My advice to you is to make sure that whatever your topic, your writing style and content is personal. Everything you say should help the readers of your file get to know you as real person, especially those intangible qualities that can't be easily understood elsewhere, including creativity, leadership, sense of humor, passion, compassion, intellectual curiosity, self-awareness, social-awareness, and more. Your personal statement is not just an essay or writing sample, it's our way of getting to know you and what you'll bring to Dartmouth.