Atomic Theory

6. The "center" of an atom in which scientists expect to find protons and neutrons, but not electrons
9. Dmitri Ivanovich Mendeleev formulated the Periodic Law, leading to the creation of this important document used by scientists around the world
10. Particles that make up an atom including protons, neutrons, and electrons
11. One of more then 110- known fundamental building blocks of matter - these particles cannot be broken down by chemical means
14. This number tells you the valence electrons of an elements on the periodic table
15. The location of electrons in an atom
16. A minute portion of matter; an individual unit of matter that could be anything from an atom to a planet depending upon established parameters
17. He laid the foundation for modern atomic theory
19. A neutral subatomic particle located in the nucleus of an atom, having a mass of 1 AMU and serving to "bind" the nucleus together

1. This scientist conducted the Gold Foil Experiment, which proved that atoms contain a nucleus and are largely made up of empty space
2. Electrons in the outermost shell
3. Created the modern model of the atom
4. Equivalent to the number of protons
5. The sum of protons and neutrons
7. A group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.
8. This scientists concluded that electrons sat in the positively charged atom
9. A positively-charged subatomic particle having a mass of 1 AMU and located in the nucleus of an atom
12. A negatively charged particle found outside of the nucleus of an atom
13. This number tells you the energy level of an element on the periodic table
18. The basic unit of a chemical elements
19. This scientist created a model of the atom similar to planets orbiting a star. The nucleus was the star, and the planets were the orbitals