Bohr believed that light is emitted by an electron when

a. the electron completes a revolution in its orbit.

b. the electron's energy changes.

c. the electron's fixed orbit shifts.

d. the electron changes direction in its orbit.

When convection currents flow in the mantle they also move the

Which of the following about the biosphere is true? a. It only interacts with the atmosphere. b. It includes oceans, lakes, rivers, and groundwater c. It can be considered a global ecosystem. d. It includes the core, mantle, and crust.

What happens to an atom of a particular element if it somehow loses a proton? A. It becomes more positive. B. A new element is formed. C. It automatically loses an electron too. D. A nearby neutron turns into a proton to replace it.

Near the end of a marathon race, the first two runners are separated by a distance of 41.6 m. The front runner has a velocity of 3.4 m/s, and the second a velocity of 4.85 m/s.

What is the part of a transverse wave where the wave is packed together? Rarefraction Compression

Explain why generators are an important use of electromagnets.

What is mummification?

Order the steps to describe how information is sent. A signal is produced. A signal is seen, heard, or used. Radio waves are modulated and amplified. Radio waves are amplified and demodulated.

The national grid supplied a house with 18000000 J of energy in 1 hour. What was the average current supplied to the house in that hour? Write any equations that you use.

Claudia throws a baseball to her dog. Which free-body diagram shows the baseball when it's flying horizontally in midair? (Assume no air resistance.)