Across
- 3. ionic structure of a substance, to a change in physical form or a nuclear reaction.
- 7. equivalent to the number of protons and neutrons in the atom (the mass number)
- 8. is a tiny particle of matter that is smaller than an atom and has a negative electrical charge.
- 9. system described by quantum mechanics, such as a molecule, atom, electron, or nucleus.
Down
- 1. distribution of electrons of an atom or molecule
- 2. is an energy level defined by quantum theory system of ideas
- 4. the number of protons in the nucleus of an atom
- 5. the organized array of all the chemical elements in order of increasing atomic number
- 6. form positive ions in chemical reactions