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35 Cards in this Set
- Front
- Back
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What is macroscale?
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things we can easily see with the naked eye or with the aid of a light microscope.
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What is nanoscale?
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The scale on which atoms and molecules exist (<10^-9 m)
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What is a pure substance?
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A sample of matter with a characteristic set of properties that does not change with further purification.
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What are the two types of pure substances?
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Elements and compounds
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What is an element?
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A pure substance that cannot be decomposed into simpler substances.
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What is a compound?
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A chemical combination of two or more elements.
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What is the basic unit of an element?
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The basic unit of an element is an atom.
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What is the basic unit of a compound?
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The basic unit of a compound is a molecule.
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What elements exist as diatomic molecules?
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H, N, O, F, Cl, Br, and I
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What is a mixture?
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A physical combination of two or more pure substances.
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What are the two mixtures?
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Homogeneous mixture(solution) and heterogeneous solution
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What is a homogenous solution?
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Evenly distributed throughout. ie) NaCl in water
milk |
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What is a heterogenous solution?
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Unevenly distributed throughout. ie) beach sand, orange juice, spoiled milk
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What are physical properties?
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Properties which can be measured without changing the compostition of the substance. These include:
melting point, boiling point, volume, hardness, density |
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What two categories can physical properties be divided into?
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Intensive and extensive
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What are intensive physical properties?
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Properties that are independent of the amount of substance present. ie) hardness, color
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What are extensive physical properties?
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Properties that depend on the amount of substance present. ie) mass, volume
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What are chemical properties?
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properties which describe the kinds of chemical reactions substances undergo. Chemical changes(reactions) produce new substances. ie) burning paper
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What are physical changes?
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Changes that occur without changing the compostition of the substance. ie) melting ice, boiling water
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What are chemical changes?
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Changes which result in a change in the chemical composition of a substance.
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Kilo
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10^3
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Deci
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10^-1
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Centi
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10^-2
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Milli
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10^-3
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Micro
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10^-6
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Nano
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10^-9
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What is an isotope?
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Atoms having the same number of protons, but different numbers of neutrons.
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What are ions?
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Atoms that have gained or lost electrons. Ions have a positive or negative charge.
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What is a cation?
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An ion with a positive charge
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What is an anion?
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An ion with a negative charge
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How does metallic character increase on the periodic table?
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Metallic character increases going down and to the left.
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What did John Dalton do?
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He proposed the first atomic model of matter that associated atoms with elements and molecules with compounds.
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What did J. J. Thomson do?
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He did experiments with cathode ray tubes and was able to measure the charge-to-mass ratio of elements but was unable to determine the charge of a single electron. He proposed the "Plum Pudding" model.
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What did Robert Millikan do?
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He was able to determine the charge of an electron with the oil drop experiment and the mass of an electron.
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What did Ernest Rutherford do?
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Used the gold foil experiment and discovered the atomic nucleus and proved the existence of protons.
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