How many sodium atoms does 3Na2S2O3 have?

(apex) when a cup of water is dropped, as the cup falls, the water in the cup falls out true or false?

In the millikan oil drop experiment they determined that every drop had a charge which was a while number multiple of -1.60x10^-19. if a drop has a total charge of -9.60x10^-19 then how many excess electrons are contained within the drop?

The chemical formula for emerald is be3al2(sio3)6.an emerald can be decided as