Which type of microscope uses a beam of electrons to examine a specimen?

If element x has 99 protons how many electrons does it have

Abaseball is thrown from the outfield toward the catcher. when the ball reaches its highest point, which statement is true? (a)its velocity is not zero, but its acceleration is zero. (b) its velocity and its acceleration are both zero. (c) its velocity is perpendicular to its acceleration. (d) its acceleration depends on the angle at which the ball was thrown. (e) none of the above statements are true.

Avehicle accelerates from 0 to 30 m/s in 10 seconds on a straight road