Is boiling point a useful identifying a substance?

Which sentence about particles in matter is true? a. atoms are present in solids and liquids but not in gases. b. the particles of matter are in constant motion. c. the same kinds of atoms are found in different elements. d. when a solid changes to a liquid, the sizes of the particles change.

What term describes technology that operates on an atomic level

As changes in energy levels of electrons increase, the frequencies of atomic line spectra they emit