Atomic Structure

Question 1

What is an ion?

Answer 1

A charged atom

Question 2

What is a cation?

Answer 2

Atoms with fewer electrons than protons, so overall positive charge

Question 3

What is an anion?

Answer 3

Atoms with more electrons than protons, so overall negative charge

Question 4

Relative isotopic mass

Answer 4

The mass of an isotope compared with one-twelfth of the mass of carbon-12

Question 5

Relative atomic mass

Answer 5

The weighted mean mass of an atom of an element compared with one-twelfth of the mass of carbon-12

Question 6

Carbon-12 mass

Answer 6

1.992x10^-26 -> one mole of carbon = 12kg, 1 atom of carbon = 12u

Question 7

How does mass spectroscopy work?

Answer 7

Place sample in mass spectrometer, sample is vaporised and ionised to form positive ions. Ions accelerate and the heavier ions will move slowly than the lighter ones, so isotopes separate. Ions are recorded using mass-to-charge ratio with each ions that reaches the detector, it add a signal.

Question 8

Mass spectrometry equation

Answer 8

M/Z = relative mass of ion/relative charge of ion

Question 9

what does weighted mean mass take into account?

Answer 9

Percentage abundance of each isotope and the relative mass of each isotope