<h3>The average atomic mass of Iodine : 126.86 amu</h3><h3>Further explanation</h3>
Given
80% 127I, 17% 126I, and 3% 128I.
Required
The average atomic mass
Solution
The elements in nature have several types of isotopes
Atomic mass is the average atomic mass of all its isotopes
Mass atom X = mass isotope 1 . % + mass isotope 2.% + ... mass isotope n.%
Atomic mass of Iodine = 0.8 x 127 + 0.17 x 126 + 0.03 x 128
Atomic mass of Iodine = 101.6 + 21.42 + 3.84
Atomic mass of Iodine = 126.86 amu
Answer: [A]: "<span><span>two atoms, both the same element, bonded together</span>".
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The family on the periodic table that has a filled outer
energy level is VIIIA. The answer is letter D. They are also called the noble
gases or inert gases. They are virtually unreactive towards other elements or
compounds. They are found in trace amounts in the atmosphere. Their elemental form
at room temperature is colorless, odorless and monatomic gases. They also have
full octet of eight valence electrons in their highest orbitals so they have a
very little tendency to gain or lose electrons to form ions or share electrons with
other elements in covalent bonds.
