You visited us 176 times! Enjoying our articles? Unlock Full Access!

Physical Properties of Boron Family

Cu has only t...

Question

$C u$ has only two naturally occurring isotopes, $63_{C u}$ and $65_{C u}$ . If the atomic mass of $C u$ is $63.546$ , then the natural abundance of the $^{63} C u$ isotope will be approximately :

10 %

No worries! We‘ve got your back. Try BYJU‘S free classes today!

30 %

No worries! We‘ve got your back. Try BYJU‘S free classes today!

50 %

No worries! We‘ve got your back. Try BYJU‘S free classes today!

70 %

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Open in App

Solution

The correct option is D $70 %$
Let the natural abundance of $^{63} C u$ isotope be $x %$ .

The natural abundance of $^{65} C u$ isotope will be $100 - x$ .

The average atomic weight is $63.546$ g.
Hence, $100 \times 63.546 = 63 x + 65 (100 - x)$
$6354.6 = 63 x + 6500 - 65 x = 6500 - 2 x$
$2 x = 145.4$
$x = 72.7 ≃ 70$
Hence, the natural abundance of the $^{63} C u$ isotope must be approximately $70 %$ .

So, the correct option is $D .$

Suggest Corrections

Similar questions

1)copper has two naturally occurring isotopes copper 63 has an atomic mass of 62. 9 296 u and an abundance of 69. 1 5% what is the atomic mass of the second isotopic if the average atomic weight of copper is 63?

Q. Chlorine has two naturally occurring isotopes,

^{35} C l

and

^{37} C l

. If the atomic mass of Cl is

35.45

, the ratio of natural abundance of

^{35} C l

and

^{37} C l

is closest to:

Q. A naturally occuring sample of copper consists of 69.2% of

^{63} C u

and 30.8% of

^{65} C u

. The relative mass of

^{63} C u

is 62.93 and that of

^{65} C u

is 64.93. Find the atomic mass of a naturally occuring sample of copper.

Q. An element (

X

) has two naturally occurring isotopes

^{90} X

has an abundance of

75

% and

^{94} X

has an abundance of

25

%. What is the average atomic mass of element

X

Q. Indium (atomic weight = 114.82) has two naturally occurring isotopes, the predominant one form has isotopic weight 114.9041 and abundance of 95.72%. Which of the following isotopic weights is the most likely for the other isotope?

Join BYJU'S Learning Program

Cu has only two naturally occurring isotopes, 63Cu and 65Cu. If the atomic mass of Cu is 63.546, then the natural abundance of the 63Cu isotope will be approximately :

$C u$ has only two naturally occurring isotopes, $63_{C u}$ and $65_{C u}$ . If the atomic mass of $C u$ is $63.546$ , then the natural abundance of the $^{63} C u$ isotope will be approximately :