Matter Test I - Review Anything that has mass and takes up space the amount of matter contained in an object the amount of space an object occupies length x width x height water displacement method the concentration of matter contained in an object has a definite shape and volume, molecules are close together has a definite volume but no definite shape but takes the shape of its container has no definite shape or volume, molecules are spread far apart and move quickly smallest unit of an element the center of an atom a particle found in the nucleus that has a positive charge a particle that orbits the atom and has a negative charge a particle found in the nucleus that has a neutral charge substance made up of only one type of atom two or more atoms joined together +