Daniel R. Barnes Chemistry 2/12/2016 8:22:52 PM Name: _______________________________________ Seat: ____ Per: _____ Date: _______________________________________ Bond Type Prediction Eliminator ANSWERS (this page): atoms, attraction, bonds, covalent, electrons, electrostatic, forces, marriage, molecules, negative, neutrons, nuclei, oxygen, pair, protons, repel, repulsion, Siamese, water BONDING IN GENERAL 1. Sometimes, two atoms that get close enough to each other will feel so attracted to each other that they will stick together for a long period of time, travelling together like ____________________________________________ twins (if they travel at all). 2. When _____________________________________ stick to each other like this, they are said to have “bonded” to each other. A “bond” has formed between them. 3. There are many kinds of bonds that can form between people, such as kinship, ___________________________________________, friendship, business partnership, or the “camaraderie of the trenches” that forms between soldiers who fight side by side in a war. 4. There are three main kinds of ______________________ that can form between atoms: ionic bonds, metallic bonds, and covalent bonds. 5. All three major kinds of bonding involve electric charges and the electrostatic _____________________________________ that electricallycharged particles feel for one another. 6. All atoms in the universe are made from a very simple list of just three ingredients: __________________________, neutrons, and electrons. 7. Protons have a positive electric charge, electrons are negative, and ______________________________________ have no charge. 8. Positive charges are attracted to _____________________________________________ charges and vice versa, lending weight to the saying that “opposites attract”. 9. On the other hand, in a phenomenon called “electrostatic _____________________________________________”, positively-charged objects push other positively-charged objects away from them. 10. Not surprisingly, negatively-charged objects electrostatically __________________________________ other negatively-charged objects. 11. Because atoms have both positive protons and negative electrons in them, there will be both ____________________________________________ attractions and repulsions between the various particles of any two given atoms. 12. The positive protons in the ____________________________________ of both atoms will repel each other, and the negative electrons orbiting those nuclei will repel each other as well. 13. However, the nuclei of both atoms will be attracted to the electron _________________________________ that the two atoms share, causing the two nuclei to bond to each other indirectly in spite of the fact that they are both positive. 14. If they are to bond, two atoms can feel both ____________________________________________ and repulsion for each other, but the attraction must be stronger than the repulsion, or the two atoms will wander or even fly away from each other. COVALENT BONDING: EXCLUSIVE SHARING WITHIN MOLECULES ( . . . and network solids like diamond and graphite . . . ) 15. It is well known that atoms often stick together to form _____________________________________________. 16. One of the most famous molecules is H2O, the _____________________________________ molecule. 17. A hydrogen atom and an ____________________________ atom in the same water molecule bond to each other by sharing an electron pair with each other, and though they may share other pairs with other atoms, they share that particular electron pair with only each other. 18. In general, any two atoms will share one, two, or even three pairs of _____________________________________________ with each other if it helps them both achieve a stable “octet” of eight electrons in their outermost, or “valence” shell. 19. Because sharing can be thought of as co-ownership, and because the electrons shared between two bonded atoms in a molecule always come from the “valence” shells of the atoms, the bond is called a “________________________________________________” bond. (It can also be thought that a covalent bond is a way for the valence shells of two atoms to merge together to form one massive supershell.) Bond Type Prediction Worksheet, Daniel R. Barnes, Chemistry, 11/10/05 10:55:11 AM ANSWERS (this page): atoms, bonds, cations, cesium, chemical, covalently, earth, electronegativity, element, greater, ionic, metal, molecule, negative, oxymoron, people, polar, positive, rating, sea, share, steal, thief, wander POLAR vs. NON-POLAR COVALENT BONDS 20. As with many of the things that __________________________________________ in the same family share, such as phones, televisions, and bathrooms, the electron pairs that atoms in the same molecule share are not always shared equally. 21. If two covalently-bonded atoms are from the same _________________________________________, they will, of course, share electron pairs with perfect equality, 50/50, forming a “nonpolar” covalent bond. 22. However, if two atoms from different elements ______________________________________________ bond to each other, one of the two atoms almost always gets a greater than 50% share of the electron pair. The atom with the higher electronegativity will be the electron hog, and the atom with the lower electronegativity will be electron-poor. 23. “Electronegativity” is the tendency of an atom to draw electrons toward itself when it forms ____________________ with other elements. 24. Electronegativity is not a directly measurable quantity, but is, rather, a somewhat arbitrary _____________________________________ system developed most famously by Linus Pauling, a Nobel Prize-winning chemist, many decades ago. 25. Linus Pauling’s electronegativity scale goes from zero to four, with the lowest elements, ________________________________ and francium, having ratings of 0.7, and the highest element, fluorine, having a rating of 4.0. 26. In general, if the difference in electronegativity between two covalently-bonded atoms is 0.4 or _________________________________, the bond will be considered “polar” covalent. 27. In a ______________________________________ covalent bond, the more electronegative atom develops a significant negative charge, and the less electronegative atom develops a significant positive charge. 28. Just as the ______________________________________ has two opposite ends, a north and a south pole, a polar bond has two opposite ends, a plus pole and a minus pole. 29. If two covalently-bonded atoms have an ______________________________________________________ difference of less than 0.4, the two atoms share electrons so close to equally that the bond is said to be “nonpolar” covalent. IONIC BONDS: OUTRIGHT THEFT 30. If two atoms have different enough electronegativity ratings, the one with the higher electronegativity will refuse to __________________ electrons with the less electronegative atom, and will, instead, completely steal one or more electrons from the less electronegative atom. 31. Generally, the electronegativity difference must be greater than 2.1 for one atom to _______________________ electrons from the other. 32. When one atom steals one or more electrons from another atom, the ______________________________ and the victim become “ions”. 33. An “ion” is either an atom or a _______________________ that has a charge due to not having equal numbers of protons and electrons. 34. _________________________________ ions, called “anions”, have more electrons than protons, and get that way by stealing electrons. 35. ________________________________ ions, called “cations”, have more protons than electrons, and get that way by giving up electrons. 36. There is no such thing as a neutral ion. “Neutral ion” is as much of an _____________________________________ as “jumbo shrimp”, “civil war”, “the living dead”, “random pattern”, “illegitimate child”, or “salt molecule”. 37. When two ____________________ refuse to share electrons, but resort to giving and taking instead, the atoms will form an “ionic” bond. 38. In ____________________________________ bonding, a positive cation is strongly attracted to a negative anion. 39. In ionic bonding, the _____________________________________ and anions are electrostatically attracted to each other so hard that they stick together, probably becoming part of a crystal that contains many other ions like them arranged in a repeating pattern. METALLIC BONDING: ELECTRONIC GLUE 40. In metallic bonding, which is not truly a _____________________________________ bond, but merely a physical bond, a whole bunch of metal atoms clump together and share their outermost electrons with each other. 41. By giving up their outermost electrons, which are negative, the ___________________________ atoms become positively-charged ions. 42. Those electrons are free to ______________________________________ all over, not belonging to any particular atom or pair of atoms. 43. These wandering electrons form a “glue” that indirectly bonds adjacent metal ions to each other, thereby holding the piece of metal together. The metallic cations are repelled by each other’s positive charges, but they are attracted to the negative “____________________” of electrons that flows between them. page 2