The spectra for elements are

a. all the same
b. the same for a chemical family
c. the same for elements with similar mass
d. all different and specific to each

Which of the following elements is in the same period as phosphorus? a. carbon c. nitrogen b. magnesium d. oxygen select the best answer from the choices provided a b c d

When the force acting on an object points at least partially in the direction of the motion the work done is considered to be negative

What energy transformations occur each time the skateboarder rolls up the ramp?