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An isotope has a mass number of 72 and an atomic number of 34. How many neutrons are in each atom of the isotope?  [red4] How many electrons are in each atom?  [red5] If the isotope gained 2 electrons, what would its charge be?  [red6] Such an ion is called a(n)  [red7]

Write a balanced equation for the complete combustion of the following substance as shown below. If the coefficient is one put 1 in the answer block   [dog5]C6H14 + [dog6]O2 –> [dog7]CO2 + [dog8]H2O

Use your calculator to complete the following calculations. Give your answer with the correct number of significant figures.   36.6 / 0.0750             [jim5]   848.8 x 0.6250              [jim6]   (1.206 x 1013) / (6.00 x 106)     [jim7]   (27.001 – 12.866) / 5.000              [jim8]

For the following equation determine the oxidation number for each atom in the equation and identify whether the reaction is a redox reaction or not. If the reaction is redox, identify what is oxidized, what is reduced, the oxidizing agent, and the reducing agent.   2Cr + 3CuSO4 –> Cr2(SO4)3 + 3Cu   Reactants Oxidation Numbers:   Cr       [cat1]   Cu       [cat2]   S          [cat3]   O         [cat4]   Product Oxidation Numbers   Cr       [cat5]   Cu       [cat6]   S          [cat7]   O         [cat8]   Is this a redox reaction?            [cat9]   If it is, what is element is oxidized?  [cat10]   What element is reduced?       [cat11]   What element is the oxidizing agent?          [cat12]   What is the reducing agent?                [cat13]

Which of the two objects or substances has the higher energy? Answer with a number, 1 or 2.   A methane molecule, CH4, in the stratosphere or A CH3 molecule and a hydrogen atom formed from breaking one of the carbon-hydrogen bonds in a CH4 molecule? [dog9]   A water molecule moving at 1.63 x 102 mi/hr or the same water molecule moving at 1.81 x 103 mi/hr. [dog10]   Iodine solid or Iodine gas (assume the two systems are at the same temperature) [dog11]   A water molecule moving at 1.63 x 103 Mi/hr or a uranium hexafluoride, UF6, molecule moving a the same velocity. [dog12]

The mass (in grams) of an atom is very small. The mass of the protons, neutrons, and electrons that make it up are smaller yet. In order to make these small values easier to use, chemists devised what?

The earth weighs about 1 x 1021 tons. Convert this to gigagrams. (There are 2000 pounds to a ton).

Write the names for each of the following compounds. CdI2  [ann5] Ca3P2  [ann6] Au(OH)3  [ann7]   FeCl2  [ann8]

Write the names for each of the following compounds. ClO2  [ann1] C2H6  [ann2] HF  [ann3] BrCl  [ann4]

Are the electrons in the following redox reactions transferred completely form the atoms of one element to the atoms of another or are they only partially transferred? Answer partial or complete.   2K + F2 –> 2KF  [ans9]   2H2 + O2 –> 2H2O     [ans10]   Ca + Cl2 –> CaCl2      [ans11]   4 Cu + O2 –> 2Cu2O   [ans12]