Question

Copper has two naturally occurring isotopes, ⁶³Cu (isotopic mass = 62.9296 amu) and ⁶⁵Cu (isotopic mass = 64.9278 amu). If copper has an atomic mass of 63.546 amu, what is the percent abundance of each isotope?

Answer 1

Copper has two naturally occurring isotopes, ⁶³Cu (isotopic mass = 62.9296 amu) and ⁶⁵Cu (isotopic mass = 64.9278 amu). If copper has an atomic mass of 63.546 amu,

Abundance of ⁶³Cu and ⁶⁵Cu ; 70% , 30.848%

Calculation :

Let the natural abundance of  63,  Cu isotope be x%.

The natural abundance of  

65

Cu isotope will be 100−x.

The average atomic weight is 63.546 g.

Hence, 100×63.546=63x+65(100−x)

6354.6=63x+6500−65x=6500−2x

2x=145.4

x=72.7≃70

Hence, the natural abundance of the  63Cu isotope must be approximately 70%.

For the ⁶⁵Cu calculation is same and the answer is 30.848%

What is isotope ?

Isotopes are members of a family of elements that all have the same number of protons and different numbers of neutrons. The number of protons in the nucleus determines the atomic number of an element on the periodic table.

Example : Magnesium has three natural isotopes : ²⁴Mg, ²⁵Mg, and ²⁶Mg.

What is Atomic mass ?

Atomic mass is the mass of an atom. The SI unit of mass is the kilogram, while atomic mass is often expressed in the non-SI unit dalton (synonymous with uniform atomic mass unit). 1 Da is defined as 1/12 the mass of a free carbon-12 atom at rest in the ground state.

To know more about Atomic mass please click here : brainly.com/question/338808

#SPJ4