June 2023  Chemistry Regents #31-35

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Questions 1-5 Questions 6-10 Questions 11-15 Questions 16-20 Questions 21-25 Questions 26-30 Questions 31-35 Questions 36-40 Questions 41-45 Questions 46-50

Questions 51-52 Questions 53-54 Questions 55-57 Questions 58-60 Questions 61-63 Questions 64-65 Questions 66-69 Questions 70-73 Questions 74-78 Questions 79-81 Questions 82-85

   

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Explanations
2   nitrogen's electron configuration is

2-5

5 dots around the N
32 The atomic masses and natural abundances of the two naturally occurring isotopes of silver are shown in the table below.
Isotope Atomic Mass (u) Natural Abundance (%)
Ag-107 106.905 51.8
Ag-109 108.905 48.2

Which numerical setup can be used to calculate the atomic mass of silver?     

            1. (106.905 u)(51.8) + (108.905 u)(48.2)

            2. (106.905 u)(51.8%) + (108.905 u)(48.2%)

            3. (106.905 u)(48.2) + (108.905 u)(51.8)

            4. (106.905 u)(48.2%) + (108.905 u)(51.8%)

 2   This is the question on this test that threw everyone off. Not hard, but annoying.

Usually you would move the decimal over and remove the % sign, or leave the % and divide it all by 100%.  Neither is a choice.

this setup would be marked wrong on my class test as it requires additional mathematical calculations to determine the atomic mass.

Note**  can be used
33A potassium atom has a mass number of 37. What is the number of neutrons in this atom?

            1. 15

            2. 18

            3. 22

            4. 37

 2   Neutrons =mass number -atomic number

so 37-19=18

 

34 At room temperature, a student determines the density of a sample of nickel to be 9.79 g/cm3. Based on Table S, what is the student's percent error for the density of nickel?

            1. 0.091%

            2. 0.10%

            3. 9.1%

            4. 10.%

 4   Table S the accepted value for the density of Ni is 8.90g/cm3.

percent error Table T

((9.79-8.90)/8.90) *100%=10%
35Compareed to the metals in Period 2, the nonmetals in Period 2 have

            1. lower first ionization energy and lower electronegativity values

            2. lower first ionization energy and higher electronegativity values

            3. higher first ionization energy and lower electronegativity values

            4. higher first ionization energy and higher electronegativity values

 4   Metals on the left and nonmetals on the right of the PT.  Pick one on each side from period 2 and look up the values on Table S and compare them.

 

Questions 1-5 Questions 6-10 Questions 11-15 Questions 16-20 Questions 21-25 Questions 26-30 Questions 31-35 Questions 36-40 Questions 41-45 Questions 46-50

Questions 51-52 Questions 53-54 Questions 55-57 Questions 58-60 Questions 61-63 Questions 64-65 Questions 66-69 Questions 70-73 Questions 74-78 Questions 79-81 Questions 82-85

  

 
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