2.1.1- Atomic Structure And Isotopes

Question 1

What is a mass number?

Answer 1

Sum of protons and neutrons in an atom

Question 2

What is the atomic number?

Answer 2

Equal to the number of protons in an atom

Question 3

What is an isotope?

Answer 3

Atoms of the same element with the same atomic number, but with a different number of neutrons

Question 4

What is the relative atomic mass?

Answer 4

The weighted mean mass of an atom of an element relative to 1/12th of the mean mass of an atom of Carbon-12 isotope

Question 5

How do you calculate relative atomic mass?

Answer 5

Mean mass of an atom of an element/ 1/12 x mean mass of c-12 isotope

Question 6

What is the relative isotopic mass?

Answer 6

Mass of an isotope relative to 1/12th of the mass of an atom of carbon-12

Question 7

What is the relative molecular mass?

Answer 7

The weighted mean mass of a molecule of a compound, relative to 1/12th of the mean mass of an atom of carbon-12 isotope

Question 8

What is mass spectrometry used for?

Answer 8

To identify different isotopes and find the overall relative atomic mass of an element

Question 9

What is time of flight mass spectrometry?

Answer 9

Records the time it takes for ions of each isotope to reach a detector. Using this, it produces a spectra showing each isotope present and the abundances of them.

Question 10

How do you work out the relative atomic mass using time of flight mass spectrometry?

Answer 10

Sum of (m/z x abundance) / total abundance