Chemistry pre-lab 6 – Flashcards
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Where are the valance electrons in an atom?
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in the outermost occupied shell of an atom
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How are positive and negative ions formed?
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Ions are formed when an atom either loses or gains an electron. A positive ion is formed when an element, typically a metal loses 1 or more electrons. A negative ion is formed when an element, typically a nonmetal gains 1 or more electrons
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Why are electrons shared in covalent compounds?
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Non metals tend to have high electronegativity values and thus share electrons rather than lose them. Typically if a compound has an electronegativity of less than 1.9 it is a covalent bond.
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How do the names of molecular compounds differ from the names of ionic compounds?
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Ionic compounds- Cation is named first, followed by the anion. If an ionic compound is formed with a transition metal and there are more than 1 possibleions that can be present there are two ways to name the compound (systematic and common).
Covalent Compounds- named with the least electronegative ion first and prefixes are given to both ions to indicate the number of atoms in each element present. The second ion ends in "ide"
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What are polyatomic ions?
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A charged particle with two or more atoms
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How does the number of bonded atoms around a central atom determine its shape? Include examples in your answer.
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The VSEPR model indicates that the bond angles in a molecule are determine when the valence electrons in bonds and lone pairs move as far apart as possible. Counting the groups of electrons that are shared pairs and lone pairs determine the electron geometry and bond angle forming its shape.
