I'm studying the equilibrium of forces so hard that I got confused for a sec. Is the force due to gravity included in summing up moments about a point? Or external forces are only considered in the summation of moments? Thanks!

Because atoms of elements in the same group of thbecause atoms of elements in the same group of the periodic table have the same number of neutrons, they have similar properties. select the best answer from the choices provided t fe periodic table have the same number of neutrons, they have similar properties. select the best answer from the choices provided t f