Amount of a substance: Relative Atomic mass

Question 1

What is the relative isotopic mass?

Answer 1

= mass of an atom of an isotope compared of 1/12th the mass of carbon-12.
= 1 relative atomic mass for each isotope of an element
= ALWAYS A WHOLE NUMBER
= NO UNITS.

Question 2

What is relative atomic mass?

Answer 2

= weighted mean mass of an atom of an element compared to 1/12th the mass of c-12
= weighted for the abundance of each isotope
= no unit.
= not whole numers.

Question 3

How do we calculate relative atomic mass?

Answer 3

= relative isotopic mass of isotope 1 x percentage abundance + relative isotopic mass of isotope 2 x percenrtage abudnance
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100