There are two main isotopes of chlorine. 75% of chlorine atoms have a mass number of 35, while 25% have a mass number of 37. use this information to work out the relative atomic mass of chlorine

English Chemistry
1

there are two main isotopes of chlorine. 75% of chlorine atoms have a mass number of 35, while 25% have a mass number of 37. use this information to work out the relative atomic mass of chlorine.

2

there are two main isotopes of chlorine. 75% of chlorine atoms have a mass number of 35, while 25% have a mass number of 37. use this information to work out the relative atomic mass of chlorine.

Answer: To calculate the relative atomic mass of chlorine (Cl), you can use the weighted average of the isotopes’ masses based on their abundance.

Given:

  • 75% of chlorine atoms have a mass number of 35 (isotope Cl-35).
  • 25% of chlorine atoms have a mass number of 37 (isotope Cl-37).

Now, calculate the weighted average:

Relative Atomic Mass (Cl) = (Abundance of Cl-35 × Mass of Cl-35) + (Abundance of Cl-37 × Mass of Cl-37)

Relative Atomic Mass (Cl) = (0.75 × 35) + (0.25 × 37)

Relative Atomic Mass (Cl) = 26.25 + 9.25

Relative Atomic Mass (Cl) = 35.5

So, the relative atomic mass of chlorine (Cl) is approximately 35.5 atomic mass units (AMU). This is the average atomic mass of chlorine, taking into account the natural abundance of its isotopes.