Question

estimate the atomic masses and relative abundances of the isotopes shown on the graph, ordered from lowest atomic mass to highest. answers have a 5% tolerance to allow for estimation. atomic mass of isotope (u) relative abundance (%) what is the average relative atomic mass of the element in the sample? assuming that the sample represents natural abundances found on earth, which element is the sample made up of? relative abundance (%) atomic mass (u)

Explanation:

Step1: Identify isotopes' mass and abundance

From the graph, isotope 1: mass \( m_1 = 10 \, u \), abundance \( a_1 = 20\% = 0.2 \); isotope 2: mass \( m_2 = 11 \, u \), abundance \( a_2 = 80\% = 0.8 \).

Step2: Calculate average atomic mass

Use formula: \( \text{Average Mass} = m_1 \cdot a_1 + m_2 \cdot a_2 \)
Substitute values: \( (10 \cdot 0.2) + (11 \cdot 0.8) = 2 + 8.8 = 10.8 \, u \).

Answer:

The average relative atomic mass is \( 10.8 \, u \), and the element (with natural abundance) is likely Boron (average atomic mass ~10.81 u).