Unit 1 Vocabulary

2. atoms of the same element that have the same atomic number but different atomic masses due to different numbers of neutrons
5. vertical columns of elements in the periodic table, made of elements with similar physical properties
6. a compound that produces hydrogen ions in solution
8. the total number of protons and neutrons in the nucleus of an atom
10. an element in group 8A of the periodic table, they ahave the s and p of the highest energy level filled
11. one of the group B elements that the highest occupied s and nearest d sublevels contain electrons
13. horizontal rows of elements in the periodic table
15. the weighted average of the masses of isotopes of certain elements
17. a negatively charged subatomic particle
18. a positively charged subatomic particle
19. one of a class of elements that are good conductors of heat and electric current, tend to be ductile, malleable and shiny
21. an element that tends to be a poor conductor of heat and electric current, generally have properties opposite of metals
22. a negatively charged ion
23. a unit of mass equal to one-twelfth of the carbon-12 atom

1. a tightly bound group of atoms that behave as a unitand has a positive or negative charge
3. a one or two letter symbol representation of an element
4. the region of an atom that contains the protons and neutrons
7. a postively charged ion
9. an element that tends to have properties that are similar to metals and nonmetals
10. a subatomic particle with no charge
12. an expression that indicates the number and types of atoms present in the smallest representative unit of a substance
14. the smallest particle of an element that retains its identity in a chemical reaction
16. an atom or group of atoms that have a positive or negative charge
20. the number of protons in the nucleus of an atom of an element