1.Which of the following elements has the mass spectrum represented above?.
(A) Nb
(B) Mo
(C) U
(D) Cf
A B C D
2.The mass spectrum of an average sample of a pure element is shown in the figure above. Which of the following is the identity of the element?
(A) Y
(B) Zr
(C) Nb
(D) Th
3.The mass spectrum of an element is represented above. Which of the following is most likely the identity of the element?
(A) Ga
(B) Ge
(C) Tm
(D) Lu
4.The mass spectrum of a sample of a pure element is shown above. Based on the data, the peak at represents an isotope of which of the following elements?
(A) Al with 13 neutrons
(B) Mg with 14 neutrons
(C) Fe with 26 neutrons
(D) Ti with 26 neutrons
5.The mass spectrum of element X is presented in the diagram above. Based on the spectrum, which of the following can be concluded about element X?
(A) X is a transition metal, and each peak represents an oxidation state of the metal.
(B) X contains five electron sublevels.
(C) The atomic mass of X is 90.
(D) The atomic mass of X is between 90 and 92.
6.Based on the mass spectrum of a sample of boron shown above, how many neutrons are in the most common isotope of boron?
(A) 5
(B) 6
(C) 7
(D) 11
7. Two different ionic compounds each contain only copper and chlorine. Both compounds are powders, one white and one brown. An elemental analysis is performed on each powder. Which of the following questions about the compounds is most likely to be answered by the results of the analysis?
(A) What is the density of each pure compound?
(B) What is the formula unit of each compound?
(C) What is the chemical reactivity of each compound?
(D) Which of the two compounds is more soluble in water?
8. In which of the following compounds is the mass ratio of chromium to oxygen closest to 1.62 to 1.00?
(A) CrO3
(B) CrO2
(C) Cr2
(D) Cr2O3
9.A 23.0g sample of a compound contains 12.0g of C, 3.0g of H, and 8.0g of O. Which of the following is the empirical formula of the compound?
(A) CH3O
(B) C2H6O
(C) C3H9O2
(D) C4H12O2
10.What is the empirical formula of an oxide of chromium that is 48 percent oxygen by mass?
(A) CrO
(C) CrO3
(D) CrO4
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