Question 14 On Mars, the element zircon has two isotopes, Zr156 and Zr160.84% of a sample is Zr156, which has an atomic mass of 156.8 amu, and 16% Zr160, which has an atomic mass of 159.4 amu. What is the average atomic mass of zircon on Mars? 157.2 amu 158.0 amu 159.2 amu 162.4 amu

Option A is correct = 157.2 amu

Explanation:

Given data:

Percentage abundance of Zr-156 = 84%

Atomic mass of Zr-156 = 156.8 amu

Percentage abundance of Zr-160 = 16%

Atomic mass of Zr-160 = 159.4 amu

Average atomic of Zr on Mars = ?

Solution:

Average atomic mass = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass)  / 100

Average atomic mass = (84×156.8)+(16×159.4) /100

Average atomic mass =  13171.2 + 2550.4  / 100

Average atomic mass  = 15721.6 / 100

Average atomic mass = 157.2 amu.

increased stability in the completion of fluorine's outer shell.

most historians agree that gabriel mouton, the vicar of st. paul’s church in lyons, france, is the “founding father” of the metric system. he proposed a decimal system of measurement in 1670. mouton based it on the length of one minute of arc of a great circle of the earth (now called a nautical mile, 1852 meters). he also proposed the swing-length of a pendulum with a frequency of one beat per second as the unit of length (about 25 cm). a pendulum beating with this length would have been fairly easy to produce, thus facilitating the widespread distribution of uniform standards. over the years, his work was revised, improved, and extended by a number of french scientists.

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