A sample contains 3.857 moles of nickel how many atoms of nickel does the sample contain? 

Dark-line (absorption) spectra can be used to identify the ________ present in stars.

A comet is visible because ________.

The asthenosphere is the second layer of Earth characterized by ________.

Why did Galileo’s observation that Venus showed phases like the Moon indicate that the geocentric theory of the solar system was not possible?

What was Hubble’s major contribution to Cosmology?

The ________ scale is an earthquake magnitude scale is based on the energy released by the earthquake.

Which of the following best describes melting of the mantle at subduction zones that leads to island arc volcanoes?

The next large earthquake on the San Andreas Fault zone in California is considered likely to be ________.

 The correlation coefficient ranges from _____ to _____.