Cho 2- Atomic Structure And Isotopes

Question 1

Def of isotopes?

Answer 1

Atoms of the same element with different numbers of neutrons and different masses

Question 2

Letter used to represent atomic number?

Answer 2

Z

Question 3

Letter used to represent mass number

Answer 3

A

Question 4

Def of relative isotopic mass

Answer 4

The mass of an atom of an isotope compared with 1/12 of the mass of an atom of carbon-12

Question 5

Def of relative atomic mass (Ar)

Answer 5

The weighted mean mass of an atom of an element compared with 1/12 of the mass of an atom of carbon-12

Question 6

Def of relative molecular mass (Mr)

[def not needed but useful to understand to use the word]

Answer 6

The weighted mean mass of a molecule of a compound compared with 1/12 of the mass of a carbon-12 atom

Question 7

Def of relative formula mass

[def not needed but useful to understand to use the word]

Answer 7

The weighted mean mass of the formula unit of a compound compared with 1/12 of the mass of an atom of carbon-12

Question 8

Calculation of
% isotopic abundance from mass spectrum

Answer 8

% isotopic abundance =. Peak height
_________________________. X 100
Total height of all the peaks

Question 9

Calculation of
Mass of specific isotope in sample from mass spectrum?

Answer 9

Mass number X % abundance
______________________________
100