Chemistry – Flashcards
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Xylene, a compound with the formula C8H10, is composed of
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eight atoms of carbon and ten atoms of hydrogen.
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When Phosphorous-30 loses a positron what is the product of this radioactive decay?
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30/14Si
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Which of the following observations demonstrates that a solid sample is a compound?
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It cannot be broken down into simpler substances by physical methods.
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Calculate the density of cyclohexane if a 50.0 g sample has a volume of 64.3 mL.
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0.778 g/mL
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Atoms of 35/17 Cl contain ________ protons and ________ electrons.
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17,17
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What is the missing reactant in the reaction shown?
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4/2 He
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A chemical reaction occurs when
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a substance's structure is altered.
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Which of the following combinations represents only alkali metals?
I. Li
II. Ba
III. Rb
IV. Ca
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I + IIII
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Round the following number to 3 significant figures: 546.85 grams.
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547
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Which nuclear reaction is an example of positron emission?
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22/11Na-->22/10 Ne+0/+1B
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Elements in the Periodic Table are arranged according to
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Atomic Number
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Which of the following is an element?
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Sodium
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What is the chemical symbol for calcium?
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Ca
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The mass number of Br-81 is
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81
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The amount of matter in an object is its
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Mass
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How many O atoms are in the formula unit GaO(NO3)2?
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7
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Which elements all belong in the same group?
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F, Cl, Br
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What is the chemical symbol for copper?
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Cu
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Which is the best description of an alpha particle?
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charge +2; mass of 4 amu; low penetrating power
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Which product is formed by alpha emission from gold-185? The atomic number of gold is 79.
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181/77Ir
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Suppose that element Z has the following properties:
a. noncombustible
b. unreactive
c. colorless, odorless gas at room temperature
d. nonconductor of electricity
Element Z could be classified as a ________ and will be found on the ________ of the Periodic Table.
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non-metal; right
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Where is most of the mass of an atom concentrated?
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Nucleus
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The symbol of the element with 23 protons is
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V
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Element Z has the following properties:
a. silvery-white solid at room temperature
b. malleable
c. used as a catalyst
d. conducts electricity
Element Z can be classified as a ________ and will be found on the ________ of the Periodic Table.
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Metal; left
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If gasoline sells for 95.4 cents per liter, what is its cost on a per gallon basis?
1 L = 1.06 q
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$3.60
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What is the specific gravity of a liquid sample with a mass of 35.0 g and a volume of 14.00 mL?
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2.5
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If you bake a pizza at 450°F, what are the Celsius and Kelvin equivalents of this temperature?
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Since 32 is in Fahrenheit, you need to subtract the 32 from 450°F *before* you divide by 1.8. Then you need to use only 2 sig figs
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The half life of a specific technetium isotope is 6 hours. How much of an 192 mg sample will have decayed after 30 hours
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Your math is correct - 6 mg remain - but the question says how much has *decayed*. That would be 186 mg.
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Grain alcohol has a density of about 6.6 pounds/gallon. What is the density in g/mL?
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