Question

name: q1 chemistry: u2l6 isotope & ions review 2. use the data table below to answer the following questions. the two isotopes are of unknown element r. teacher: date: uncommon schools isotope atomic mass (amu) natural abundance 1 69.92 20.94% 2 71.92 27.54% 3 72.92 36.20% 4 73.92 7.72% 5 75.92 7.61% a. create the mass spectrum that represents element r using the data above. b. calculate the atomic mass of this element and determine its identity. make sure to use significant figures! c. based on your answer above, complete the table below. isotope nuclear symbol isotope name 1 2 3 4 5

Explanation:

Step1: Calculate the atomic mass

The atomic mass ($A$) of an element is calculated as the weighted - average of the atomic masses of its isotopes. The formula is $A=\sum_{i = 1}^{n}m_i\times p_i$, where $m_i$ is the atomic mass of the $i$-th isotope and $p_i$ is the percent abundance of the $i$-th isotope (expressed as a decimal).
For the given isotopes:
$m_1 = 69.92$ amu, $p_1=0.2084$
$m_2 = 71.92$ amu, $p_2 = 0.2754$
$m_3 = 73.92$ amu, $p_3=0.3620$
$m_4 = 75.92$ amu, $p_4 = 0.1542$
$A=(69.92\times0.2084)+(71.92\times0.2754)+(73.92\times0.3620)+(75.92\times0.1542)$
$A = 69.92\times0.2084=14.561328$
$A_1=71.92\times0.2754 = 19.707768$
$A_2=73.92\times0.3620=26.75904$
$A_3=75.92\times0.1542 = 11.706864$
$A=14.561328 + 19.707768+26.75904+11.706864=72.735008\approx72.74$ amu

Step2: Identify the element

Looking at the periodic table, the element with an atomic mass close to 72.74 amu is germanium (Ge) with an atomic number of 32.

Step3: Write nuclear symbols

The nuclear symbol of an isotope is written as $_{Z}^{A}X$, where $Z$ is the atomic number and $A$ is the mass number. For germanium ($Z = 32$):

Isotope	Nuclear Symbol	Isotope Name
2	$_{32}^{72}Ge$	Germanium - 72
3	$_{32}^{74}Ge$	Germanium - 74
4	$_{32}^{76}Ge$	Germanium - 76
5	N/A	N/A

Answer:

a. To create the mass spectrum: On the x - axis is the mass number and on the y - axis is the percent abundance. Plot peaks at approximately 69.92 amu with 20.84% abundance, 71.92 amu with 27.54% abundance, 73.92 amu with 36.20% abundance, and 75.92 amu with 15.42% abundance.
b. The atomic mass of the element is approximately 72.74 amu and the element is germanium (Ge).
c. See the table above for nuclear symbols and isotope names.