Atomic Structure and the Periodic Table: Relative Atomic Mass (DONE)

Question 1

What is the relative atomic mass?

Answer 1

The weighted average of two isotopes of the same element.
(average is weighted for abundance of each isotope)

Question 2

What does it mean if an isotope is “abundant”?

Answer 2

Abundance means how common each isotope is.

Question 3

Calculate the relative atomic mass:

10
B
5

20% abundance

11
B
5

80% abundance

Answer 3

(10 x 20) + (11 x 80)
____________________
100

Relative atomic mass of Boron = 10.8

(In the periodic table this is rounded to 11)