2 Atoms, Ions and Compounds

Question 1

What are isotopes?

Answer 1

Isotopes are atoms of the same element with different numbers of neutrons and different masses.

Question 2

What is relative isotopic mass?

Answer 2

It is the mass of an isotope relative to 1/12th the atom of carbon -12.

Question 3

What is relative atomic mass?

Answer 3

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

Question 4

How does a mass spectrometer work?

Answer 4

1) A sample is placed in the spectrometer.
2) The sample is vaporised and then ionised to form positive ions.
3) The ions are accelerated and heavier ions move more slowly and are more difficult to deflect than lighter ions, so the ions of each isotope are seperated.
4) The ions are detected on a mass spectrum as a mass-to-charge ratio m/z.
m/z= relative mass of ion/relative charge of ion