One isotope of nitrogen has 7 protons and 8 neutrons. which is the correct reference for this isotope? a. nitrogen-8 b. nitrogen-7 c. nitrogen-15 d. nitrogen-1

How does convection affect our atmosphere? our layers of earth? our oceans?

Aboxcar traveling at 12 m/s approaches a string of 5 identical boxcars sitting stationary on the track. the moving boxcar collides and links with the stationary cars and they all move off together along the track. what is the final speed of the cars immediately after the collision? (you may take the mass of each boxcar to be 18,537 kg.)

Compare the horizontal displacement of the two balls as they travel to the ground. what do you observe?