Helium and neon are elements in group 8a of the periodic table. how do the electron dot diagrams of these elements compare?

When molecules of water vapor in the air come in contact with a cold can of soft drink , they lose energy ,slow down,and form a liquid due to decrease in ?

Plz choose one of the compounds from the table and explain how you know the numbers of atoms in your formula. is it possible for two different compounds to be made from the exact same two elements? why or why not? with a limited number of elements (less than 120 are known), does this mean we also have a small number of compounds or do we have a large number of compounds in this world?

The excretory system,need answers for all: )