What is the last nuclear fusion stage in the life of a low-mass star like the sun?

What is binding energy and separation energy

Waves are used in many practical applications to support work, entertainment, and health. one example is the use of ultrasound imaging to safely track the development of a growing fetus. what is a specific example of a practical application of waves in medicine, entertainment, safety, or other fields? provide a brief explanation of how the properties of waves are useful to that application.

What causes the formation of ocean currents?