5. the element copper has naturally occurring isotopes with mass numbers of 63
and 65. the relative abundance and atomie masses are 69.2% and 30.8%
respectively. calculate the average atomic mass of copper,

63.616

Explanation:

DATA

1. first atomic mass;m1=63

SOLUTION

avg= (m1)(p1) + (m2)(p2)

100

avg= (63)(69.2) + (65)(30.8)

100

avg= 4359.6 + 2002

100

avg= 6361.6

100

avg= 63.616

the correct option is c.

isotopes refers to different forms of the same element with the same atomic number but different mass number as a result of difference in their neutron numbers. isotopes have different relative atomic mass but share the same chemical properties.