Chemistry Definitions

2. Different energy levels where electrons orbit the nucleus
11. Describes the electron moving around each shell;2,8,8,2
13. Smallest part of matter, contains protons neutrons and electrons
15. Theory that all matter is made up of matter
17. The centre of an atom-contains protons and neutrons
18. A substance that contains 2 or more types of atoms
20. An atom or group of atoms that carries a positive or negative electric charge as a result of having lost or gained one
21. A model of an atom made by Niels bohr

1. Negatively charged particles found orbiting the nucleus of an atom
3. A substance that contains only 1 type of atom
4. The area around the nucleus where the electrons travel
5. Positively charged particles in the nucleus of an atom
6. Total number of protons in an atom; defines which atom it is
7. Vertical column on the periodic table
8. Horizontal row on the periodic table
9. A table that lists all the elements in order of their atomic number
10. Parts that make up an atom
12. The mass of an atom; equals the number of protons plus the number of neutrons
13. Negatively charged ions.
14. Neutral particles in the nucleus of an atom
16. Atoms that have the same number of protons and electrons but different numbers of neutrons
19. Positively charged ions.