Periodic Table

2. the outermost shell of an atom
4. an organized way to organize different chemical elements
7. fluorine, chlorine, bromine, iodine and astatine are these
8. a group of elements have the same number of valence electrons and similar chemical properties
10. a particle with a positive charge
11. an atom with a
12. the mass of an atom
13. outer shell electron that is associated with an atom
15. This can either be positive or negative
17. a particle with a negative charge
19. the brain or most important part of an object
20. the number of protons in an atom's nucleus
21. made up of protons neutrons and electrons
22. a positively charged ion

1. six chemical elements in group two of the periodic table.
3. chemical element which has a mixture of properties of metals and nonmetals
5. a particle with a neutral charge
6. Radium,iron, and sodium are examples of this
9. two of the same element that has the same number of
14. where electrons are when they go around the nucleus of an atom
16. lithium, sodium, potassium, rubidium, cesium, and francium are example of this
18. hydrongen and carbon are examples of this
20. a negatively charged ion