Home › Forums › setting the stage › solids as quantum systems › Definition of solids This topic has 0 replies, 1 voice, and was last updated 2 years, 2 months ago by mmahmoud. Viewing 1 post (of 1 total) Author Posts October 12, 2022 at 2:30 pm #7145 mmahmoudParticipant A solid is a three-dimensional structure of arranged atoms. solid is one of 3 or more generally 4 states of matter, namely gas, liquid, and plasma. Author Posts Viewing 1 post (of 1 total) You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In