Question

1. chlorine has two possible isotopes. you must use at least one atom of each isotope. what combination of the number of atoms and isotopes will come closest to the actual average atomic mass of 35.45? show your combination below. what does this mean about the percent abundance of these isotopes? (remember, the 2 percent values must add up to 100%) cl - 35 atoms % cl - 37 atoms %

Explanation:

Step1: Set up the equation

Let the percentage abundance of Cl - 35 be $x\%$, then the percentage abundance of Cl - 37 is $(100 - x)\%$. The average atomic mass of chlorine is calculated by the weighted - average formula: $35x+37(100 - x)=35.45\times100$.

Step2: Expand the equation

Expand $35x+37(100 - x)=35.45\times100$ to get $35x + 3700-37x=3545$.

Step3: Simplify the equation

Combine like - terms: $35x-37x=3545 - 3700$, which gives $- 2x=-155$.

Step4: Solve for x

Divide both sides of the equation $-2x=-155$ by $-2$, so $x = 77.5$. Then $100 - x=100 - 77.5 = 22.5$.

Answer:

Cl - 35 atoms: 77.5%
Cl - 37 atoms: 22.5%