periodic table

3. the smallest unit of a compound.
5. the force that hold atoms together in compounds.
7. the average mass of an atom of an element.
10. the central core of an atom containing protons and neutrons
12. a positively charged subatomic particle in the nucleus.
14. a fundamental substance with a unique atomic number
16. a substance formed when two or more different elements combine chemically.
19. atoms of the same element with different numbers of neutrons.
20. a neutral subatomic particle in the nucleus.
22. an element that does not conduct heat and electricity well.
25. an atom or molecule with a net electrical charge due to loosing or gaining electrons.
26. a negatively charged subatomic particle that orbits the nucleus.

1. an element with properties of both metals and nonmetals.
2. a highly reactive group of nonmeatls in group 17.
4. an organized arrangement of elements displaying trends in their properties.
6. The smallest unit of an element that retains the elements properties.
8. a vertical column in the periodic table
9. an electron in the outermost shell of an atom.
11. a group of unreactive nonmetals in group 18.
13. a measure of an atoms ability to attract electrons in a chemical bond.
15. elements in group 3-12 of the periodic table
17. a horizontal row in the periodic table.
18. a group of highly reactive metals in group 1
21. the number of protons in and atoms nucles.:
23. an element that conducts heat and electricity well.
24. the principle that the properties of elements are functions of their atomic numbers.