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12 Cards in this Set
- Front
- Back
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What is the law of Octaves?
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When elements were arranged by atomic mass every 8th element had similar properties. This law was adequate up to 20 elements but did not hold up part 20 (Ca).
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Mendeleev's periodic table?
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Grouped elements more accurately
Made possible the prediction of the properties of several elements that had not yet been discovered. |
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What were some problems with the early periodic table?
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Argon has a larger atomic mass than potassium which could not really be explained
This was explained when atomic number was discovered |
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What does the modern periodic table show?
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Shows atomic number and element symbol
The electron configurations of elements help explain the recurrence of physical and chemical properties |
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Why is the periodic table important?
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Important because helps us understand general properties and trends within a group or period
Also helps to predict properties of any element even if we are not familiar with the element |
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What is classification of elements based on?
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Filling of outer shell of electrons. Outer shell of electrons are called valence electrons.
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Why do elements of the same groups behave similarly?
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The reason for this is they all have the same number of electrons in their outer shell
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What area noble gases?
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Behave similary. Mostly inert, this is due to the completely filled ns and np subshells
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Transition elements classification?
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No regualar pattern of electron configuration. All transition metals share some characteristics.
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How do Lanthanides and actinides behave?
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Similarly
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Why do we always use metal's empirical formula in chemical equations?
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Because metals and metalloids do not exist as distinct molecular units
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How are nonmatals represented in chemical equations?
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No single rule
Carbon exists in extensive networks; so we use its empirical formula For the most part we use stable forms of the element to represent it Noble gases are monoatomic and thus represented by their empirical formula |
