A certain element consists of two stable isotopes....?

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A certain element consists of two stable isotopes....?

The molar mass of Isotope A is 10.0 g/mol and % abundance is 19.9 %. The molar mass of Isotope B is 11.0 g/mol and % abundance is 80.1 %.

What is the average molar mass of this element?

What element is it?

=0 Help?

2007-12-28 05:24:09 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry

2 answers

(Isotope A * %A) + (Isotope B * %B) = Element
(10.0g/mol * 0.199) + *11g/mol * 0.801) = Element
(1.99) + (8.811) = 10.801 g/mol => Boron (using a periodic table)

2007-12-28 05:27:54 · answer #1 · answered by ¿ /\/ 馬 ? 7 · 2⤊ 0⤋

10g/mol x 19.9% = 1.99

11g/mol x 80.1% = 8.81
_____________________
10.81

Boron

2007-12-28 05:34:35 · answer #2 · answered by steve_geo1 7 · 2⤊ 1⤋