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29 Cards in this Set
- Front
- Back
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how do properties of a compound compare with the properties of element that make them?
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A compound is a substance made of atoms of different elements.
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Example of properties of compounds comparing with properties of elements that make it
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Water (h20) is made from 2 atoms of hydrogen and 1 atom of oxygen. Both atoms are odorless am=nd colorless but a water molecule is a liquid at room temperature.
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What two factors determine the props. of a compound?
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How the atoms are arranged and what elements they contain.
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What can you predict about the properties of the compound potassium flouride compared to the properties of potassium chloride?
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Properties are different and unique between the two compounds
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What is an element? Give 3 examples.
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An element is a substance that cannot be broken down to a simpler substance. Example: Nitrogen, N; oxygen o; sulfer, na; potassium, K
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what is a compound? Give 3 examples
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A compound is a substance made up of 2 or more elements bonded together. Example: h20, co2, hcl
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What is a subscript?
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A # written slightly below and to the right of the chemical symbol.
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What is a chemical formula?
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An expression that shows the # and the types of atoms of the elements joined in a compound.
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How do you represent compounds?
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By a chemical formula.
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what is...NaCl
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Na=sodium Cl=chlorine
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C12H22O11
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C=carbon=12 H=hydrogen= 22 O=oxygen=11
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What is a chemical bond?
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The force of attraction between two atoms that 'glue' the atoms together.
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What part of an atom is involved in chemical bonding?
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Electrons, in particular, valence electrons or electrons found in the most outer shell..
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What is an ionic bond?
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The electronic attraction between a negative and positive ion.
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How do ionic bonds form?
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When elements with very few valence electrons (metals) react with elements with ALMOST a fulll outer shell. (nonmetals) There is a complete transfer of electrons.
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What is an ION
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Atom or group of atoms that has a positive or negative electric charge.
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How does an Ion form from an atom?
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when an electron is gained or lost
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What happens when an atom loses an electron?
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It becomes a positive ion
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What happens when an atom gains an electron?
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It becomes a negative ion
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WHat type of elements usually bond together to form ionic bonds?
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metals and nonmetals.
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What are the characteristic properties of ionic compounds.
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-Regular crystal structure
-solids at room temperature -High melting points -Hard and Brittle -poor conductors of electricity |
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How are ionic compound named?
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1, take the name of the metal element
2. take the name of the nonmetal element and give it the ending ide 3.combine the names |
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What is a covalent bond?
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A paired of shared electrons between two atoms
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how are covalent bonds formed?
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Formed from elements that did not easily gain or lose electrons BUT share electrons. The shared electrons (negative0 are attracted to the positive nuclei of each atom at the same time in a covalent bond.
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what is a molecule?
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A two or more atom joined together by covalent bonds that has all the props. of the substance created
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What makes a polar covalent bond?
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A covalent bond in which the electrons are shared equally.
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What type of elements usually bond together to form covalent bonds?
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2 nonmetals usually form unequally covalent bond.
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What are the characteristic properties of covalent compounds?
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-Atoms organized individual molecules
-low melting points. -poor conductors of electricity. |
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How can the same element look different?
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Some covalent bonds form molecules that contain hundreds of thousands of atoms
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