Chemthink.com – Ionic Formulas 1. What type of element never forms ions? 2. Why not? 3. What can we use to predict the charge of an ion? 4. A neutral sodium atom has _____ electrons. What two choices does sodium have: Lose______________ to have _____ electrons or gain_______________ to have _______ electrons. 5. Which is easier to do (and therefore sodium does it)? 6. A neutral chlorine atom has _______ electrons. What two choices does chlorine have: lose __________ to have _____ electrons or gain __________ to have _______ electrons. 7. Which is easier to do (and therefore chlorine does it)? 8. Does Barium Lose or Gain electrons? How many? What charge does Barium end up with? 9. Does Oxygen Lose or Gain electrons? How many? What charge does Oxygen end up with? 10. What kinds of atoms do we need to form an ionic compound? 11. Total number of electrons ______ = Total number of electrons _________. This fact allows us to predict __________________________________________________________. 12. What problem do Sodium and Oxygen have that Sodium and Chlorine don’t? How does this explain the formulas for each compound? 13. In the compound between Calcium and Fluorine, ____ calcium ions are needed and ______ fluoride ions which results in the following formula: ____________. 14. In the compound between Lithium and Nitrogen, ____ lithium ions are needed and ______ nitride ions which results in the following formula: ____________. 15. In the compound between Aluminum and Sulfur, ____ Aluminum ions are needed and ______ sulfide ions which results in the following formula: ____________. 16. If you feel ready, try the questions. If not, go through the tutorial again. For the questions, you must get 10 questions correct before getting 3 wrong. If you do not do this, you must start over. You may take as many attempts as needed to get your 10 correct questions. Your progress is tracked on the right side of the screen. 17. Hint: some questions have more than one answer, so look carefully at all answer choices before hitting submit. 18. You do not need to send anything to me as long as you are registered and logged into my class and complete it by the due date. Chemthink collects the info online where I can access all results.