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Chapter 4 Covalent
7th : Earth Science
Question | Answer |
---|---|
What is a polar molecule? | covalent molecule w/UNEVEN distribution of electrons, resulting in slight charges within the molecule itself |
What is a nonpolar molecule? | covalent molecule w/EVEN distribution of electrons so no net charge |
What is a hydrogen bond? | weak bond between certain kinds of molecules caused by the attraction between H atom in one molecule and unshared pair of electrons in another |
What is a covalent bond? | chemical bond that is made by SHARING electrons |
What are valence electrons? | an atom's outermost electrons |
Draw the lewis structure for beryllium (Be) | Be: |
Draw the lewis structure for selenium (Se) | .:Se:. |
How many valence electrons puts an atom in its most stable state? | 8 |
Do polar and nonpolar molecules mix well together? Why? | no |
What molecules contain delta charges? | polar molecules |
Why does water expand when it freezes? | molecules are closer together when in liquid phase (because H bonding) and actually have to move apart when moving to solid phase |
Which type of compounds have higher melting points? | ionic has higher MP then covalent |
The differences among the phases of matter depend on...??? | motion of molecules |
What is happening to the molecules in each phase of matter? | solid-little vibration, liquid-free movement, gas-molecules not touching at all ("chasing" one another) |
How do you get from solid to liquid to gas? | add energy (molecules move faster) |
How do you get from a gas to a liquid to a solid? | remove energy (molecules move slower) |
Draw the lewis structure for the compound formed by aluminum (Al) and bromine (Br) | Br- Al3+ |
Draw the lewis structure for the compound formed by sodium (Na) and chlorine (Cl) | Na+ Cl- |
Draw the lewis structure for the compound formed by Cl2 | Cl-Cl |
Draw the lewis structure for the compound formed by potassium (K) and sulfur (S) | K+ S2- |
Draw the lewis structure for the compound Br and O | Br-O-Br |
Draw the lewis strucutre for CH4 | H-H-C-H-H |