Boron has two naturally occurring isotopes: boron -10 (19.8% abundance, mass 10.013 amu ) and born -11 (80.2% abundance, mass of 11.009 amu). what is the average atomic mass of boron? show work   

Hello!

To find the average atomic mass of boron, we need to use this formula:

Average Mass = (mass of isotope #1)(percent abundance) + (mass of isotope #2)(percent abundance) + ...

Before we use the formula, we need to convert the percentages into decimals. Remember that all percentages are out of 100, so, we divide the percent by 100 to get it into decimal form.

19.8 / 100 = 0.198

80.2 / 100 = 0.802

Average Mass = (10.013 amu)(0.198) + (11.009 amu)(0.802)

Average Mass = 1.98 amu + 8.83 amu

Average Mass = 10.81 amu

Therefore, the average atomic mass of boron is 10.81 amu.

8 carbon atoms forming single bonds with 18 hydrogen atoms; a triple bond exists between the third and fourth carbon atom from the right

explanation:

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explanation:

covalent bonds

consist of pairs of electrons shared by two atoms, and bind the atoms to fixed orientation and requre high energies to break them

ionic bonds

when two atoms differ considerably in their electronegativity, then one of the atoms will lose its electron to the other atom. this results in a positively charged ion(cation) and a negatively charged ion (anion)