Answer: we can calculate the average atomic mass of the newly discovered element as 540.154 AMU.
Explanation: To calculate the average atomic mass of the newly discovered element, we will follow these steps:
1. Convert the relative abundances to decimal form:
- Relative abundance of Lunarium-538: 17.1% = 0.171
- Relative abundance of Lnuarium-540: 81.5% = 0.815
- Relative abundance of Lunarium-541: 1.4% = 0.014
2. Calculate the weighted average:
- Multiply the mass of each isotope by its relative abundance.
- Lunarium-538: 537.992 AMU x 0.171 = 92.102332 AMU
- Lnuarium-540: 540.118 AMU x 0.815 = 440.47717 AMU
- Lunarium-541: 541.003 AMU x 0.014 = 7.574042 AMU
- Sum up the weighted masses: 92.102332 AMU + 440.47717 AMU + 7.574042 AMU = 540.153544 AMU
3. Round the average atomic mass:
- The average atomic mass of the newly discovered element is 540.154 AMU when rounded to the thousandth place.
By following these steps, we can calculate the average atomic mass of the newly discovered element as 540.154 AMU.