1. Physical Science Pre-Test Chapter 19

2. Each letter or pair of letters is a _______ _______. Chemical symbol

3. Know your chemical symbols and chemical names.

4. A _______ is a combination of two or more elements. compound

5. _______ means written below. What two things does a chemical formula tell? subscript

6. _______ _______ tells which elements and the ratio of the atoms of those elements. Chemical formula

7. An element is _______ _______ if the outer energy level is completely filled. Chemically stable

8. _______ is the maximum number of electrons in an elements outermost energy level. 8

9. _______ _______ is a force that holds together the atoms in a substance. Chemical bond

10. Does a compound always have the same properties as the elements that make it up? NO

11. _______ _______ are the electrons in the outermost energy level. Valence electrons

12. _______ _______ are more chemically stable than other elements because they have a complete outer energy level. Noble gases

13. Why do most elements tend to form compounds? To become chemically stable

14. _______ are atoms that have a charge. Ions

15. _______ _______ is the force of attraction between the opposite charges of the ions in an ionic compound. Ionic bond

16. The result of bonding is a net charge of ________. zero

17. _______ is a positively charged ion. cation

18. _______ is a negatively charged ion. anion

19. _______ _______ is the attraction that forms between atoms when they share electrons. Covalent bonds

20. _______ means “having oppositely charged ends.” polar

21. _______ _______ is a molecule that has a positive end and a negative end. Polar molecule

22. _______ _______ is a molecule that does not have oppositely charged ends. Nonpolar molecule

23. _______ _______ is the apparent charge on an element. Oxidation number

24. _______ _______ is a positive or negative number assigned to an element to show its combining ability in a compound. Oxidation number

25. Left to Right across the periodic table, the number of valence electrons goes __________. 1, 2, 3, 4, 5, 6, 7, 8

26. Left to Right across the periodic table, oxidation numbers go _______________ ______. +1, +2, +3, ±4, -3, -2, -1, 0

27. _______ means two. bi

28. _______ compounds are composed of two elements. binary

29. State the rules for writing formulas for binary compounds. See notes

30. Be able to write chemical formulas when given a pair of elements. See notes

31. State the rules for naming binary compounds. See notes

32. Be able to name compounds when given a chemical formula. See notes

33. The net charge on a compound is always _______. zero

34. _______ _______ is a positively or negatively charged, covalently bonded group of atoms. Polyatomic ion

35. _______ is a compound that has water chemically attached to its ions. hydrate

36. Chemists use _______ from the periodic table to write formulas for compounds. symbols

37. _______ means “many.” poly

38. Know the Polyatomic ions. See pg 591

39. Know the prefixes used in naming molecules. See pg 593

40. Be able to name and make compounds with the Polyatomic ions. See notes