Why does the radius of an atom decrease as you go across (from left to right) a period on the periodic table? a. because you are adding less energetic electrons b. because you are adding positively charged protons, which pull in the outer electrons c. because you are adding more outer level of electrons, decreasing the area in which they can move d. because you are adding more neutrons, which increases the attraction between proton and electron

Two people each hold the end of a rope and create waves by moving their arms up and down. this wave is best classified as a transverse wave because a) both the rope particles and the wave are moving in the same direction. b) the wave is moving up and down as the particles of the rope move horizontally. c) the wave is moving horizontally as the particles of the rope move up and down. eliminate d) the wave is moving in a parallel direction with the motion of the person's arms.