B, mode since mode represents the data is the most frequent in the whole set, which in this case is 8cm
Answer:
27.2 a.m.u
Explanation:
Isotope of an element is its tendency to exist in two or more forms. Thus, the average atomic mass of the element is required. And this can be calculated by adding the individual product of the percentage isotope and its mass.
The average atomic mass of the element can be determined by:
= (70% x 26) + (30% x 30)
= (0.7 x 26) + (0.3 x 30)
= 18.2 + 9
= 27.2
Thus, the average atomic mass of element X is 27.2 a.m.u
