I do not have shape or volume. you cannot see me, but i fill any container in which i am placed. i have weight, but you cannot hold me. what am i?

The identity is a gas. Gas is a state of matter that has weight and occupies volume. Because of the wide arrangement of the molecules, they can move freely. As a result, they are invisible to the naked eye. They have mass and volume, but they usually take the shape and volume of their container.