The electron dot diagram shows the arrangement of dots without identifying the element. ? with 2 dots above and 1 dot each right, below, left.

Which element’s symbol could replace the question mark in the diagram?

boron (B)
neon (Ne)
rubidium (Rb)
arsenic (As)

Aplayground merry-go-round has a radius of 4.6 m and a moment of inertia of 200 kg-m2 and turns with negligible friction about a vertical axle through its center. a child applies a 26.0 n force tangentially to the edge of the merry-go-round for 15.0 seconds. if the merry-go-round is initially at rest, how much work did the child do on the merry-go-round?