An x-ray tube contains a target consisting of atoms with z = 44. the high voltage in this tube is increased from zero. using the bohr model, find the value of the voltage at which the x-ray just appears in the x-ray spectrum.

Which statement best summarizes Niels Bohr's complementarity principle? Light incident on a metal surface results in the emission of a photon. Light incident on a metal surface results in absorption of energy.

Describe the radioactive disintegration's known as alpha, beta, and gamma decay

How can heat produce more heat

Every time your cats paw hits her toy string, it swings away from her. How does this demonstrate Newton's third law of motion?

How long does it take for the earth to rotate

Hydroelectric power uses: wind water coal the sun

Two lightweight metal spheres are suspended near each other from insulating threads. One sphere has a net charge; the other sphere has no net charge. The spheres will: A. Attract each other B. Exert no electrostatic force on each other C.

Read the given list of organisms. squirrel, zebra, tortoise, rabbit, horse What best describes the role of these five organisms in a food web?

What are the SI units for specific heat capacity

What are starburst galaxies and what do they have to do with galaxy evolution?