Which two element are most likely in the same group

The answer would be Bismuth and Nitrogen because they have the same number of valence electrons. Groups in the periodic table are arranged in columns. When it comes to neutral atoms, the number of valence electrons it has is equal to the main group of that element.

I'm having some difficulty seeing the diagram clearly.but the question says there's a net inward force on the object.so we know right away,  from newton's 2nd law of motion, thatthat baby is accelerating.  it doesn't even matter which way thenet force is pointing.  if there's any net force, then either theobject's speed or else its direction must be changing.