Question

question 9 (1 point) chlorine 36 has an abundance of 24.22% what is the percent mass? a 8.95 g b 35.458 g c 36.59 g d 9.86 g question 10 (1 point) boron 11 is 80.1% of all boron, what is its percent mass? a 6.123 g b 20.180 g c 11.506 g d 10.811 g

Explanation:

Step1: Recall percent - mass formula

Percent mass = (mass of isotope / total mass of all isotopes)×100%

Step2: For boron - 11

We are given that boron - 11 makes up 80.1% of all boron. Let's assume we have 100 atoms of boron. Then 80.1 of them are boron - 11.
Let the mass of boron - 11 be \(m_{11}\). We are given the mass values for different options.
If we assume the total mass of all boron atoms is considered in the context of isotopic abundance, and we know the relative abundance of boron - 11.
The percent - mass of an isotope is related to its atomic mass and abundance. The atomic mass of boron - 11 is approximately 11 amu. Among the options, the value closest to the mass of boron - 11 considering its abundance and the concept of percent - mass is 11.506 g is incorrect, 20.180 g is too large, 6.123 g is too small, and 10.811 g is the average atomic mass of boron (not the mass of boron - 11 specifically). But if we consider the fact that boron - 11 has a relative atomic mass close to 11, and looking at the options in terms of mass contribution based on abundance, we assume the question is asking for the mass of boron - 11 in a sample context. The mass of boron - 11 should be close to its atomic mass value.

For chlorine - 36, we know its abundance is 24.22%. Using the same percent - mass formula, if we assume we have a sample of chlorine atoms, and we want to find the mass contribution of chlorine - 36. The atomic mass of chlorine - 36 is close to 36. Among the options 9.86 g is too small, 35.458 g is the average atomic mass of chlorine, 8.95 g is also incorrect, and 36.59 g is close to the atomic mass of chlorine - 36 considering its abundance in the sample.

Answer:

Question 10: 11.506 g (closest to the expected mass of boron - 11 considering atomic mass and context)
Question 9: 36.59 g (closest to the expected mass of chlorine - 36 considering atomic mass and context)