write a 5 Sentence summary, about how the work of various scientists, physicist, astronomers, seismologist, etc. have contributed to the understanding of the layers of the Earth.

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.

The electronic structure or chlorine is 2.8.7 what is the electronic structure of fluorine?

You've already seen the value of 9.8 in this lesson. what's this value called? what quantity does it represent?