Question

1. use the data table below to answer the following questions. the two isotopes are of unknown element r.

isotope	atomic mass (amu)	natural abundance
2	64.9378	30.83%

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!
(62.9296×69.17)+(64.9378×30.83)
4352.8 + 2002
6354.8 / 100 = 63.548 = cu copper
c. **based on your answer above, complete the table below.

isotope	nuclear symbol	isotope name
2

Explanation:

Step1: Calculate atomic mass

The atomic mass ($A$) of an element with two isotopes is calculated using the formula $A = m_1\times p_1 + m_2\times p_2$, where $m_1$ and $m_2$ are the atomic - masses of the isotopes and $p_1$ and $p_2$ are their respective natural abundances (in decimal form). First, convert the percentages to decimals: $p_1=0.6917$ and $p_2 = 0.3083$. Then, $A=(62.9296\times0.6917)+(64.9378\times0.3083)$.
$62.9296\times0.6917 = 62.9296\times(6917\div10000)=43.528$, and $64.9378\times0.3083=(64.9378\times3083\div10000)=20.02$.
$A = 43.528+20.02=63.548$ amu.

Step2: Identify the element

The element with an average atomic mass of approximately $63.548$ amu is copper (Cu).

Step3: Determine nuclear symbols and isotope names

For isotope 1 with atomic mass $62.9296$ amu, the nuclear symbol is $^{63}Cu$ (since the mass number is closest to 63), and the isotope name is copper - 63. For isotope 2 with atomic mass $64.9378$ amu, the nuclear symbol is $^{65}Cu$ (since the mass number is closest to 65), and the isotope name is copper - 65.

Answer:

a. To create the mass spectrum: On the x - axis, label "Mass number" and mark 63 and 65. On the y - axis, label "Percent Abundance". Draw a peak at mass number 63 with a relative height corresponding to 69.17% and a peak at mass number 65 with a relative height corresponding to 30.83%.
b. Atomic mass: $63.548$ amu, Element: Copper (Cu)
c.

Isotope	Nuclear Symbol	Isotope Name
2	$^{65}Cu$	Copper - 65