Answer:
The element is carbon because the atomic mass of carbon is 12.
Step-by-step explanation:
Abundance of x¹² = 98.9%
Abundance of x¹³ = 1.1%
Atomic mass of x¹² = 12 amu
Atomic mass of x¹³ = 13 amu
Average atomic mass = ?
Solution:
Average atomic mass of x= (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100
Average atomic mass of x = (12 ×98.9)+(13 ×1.1) /100
Average atomic mass of x = 1186.8 + 14.3 / 100
Average atomic mass of x = 1201.1/ 100
Average atomic mass of x = 12.01 amu.
The element is carbon because the atomic mass of carbon is 12.