3.1.1 - Atomic Structure

Question 1

Plum Pudding Model

Answer 1

Atoms consisted of a sphere of positive charge with small negative charges distributed evenly

Question 2

Electron Shell Model

Answer 2

Atom consists of a small, dense central nucleus surrounded by orbiting electrons in electron shells

Question 3

Relative Atomic Mass (Ar)

Answer 3

The mean mass of an atom of an element, divided by one twelfth of the mean mass of an atom of the carbon-12 isotope

Question 4

Isotope

Answer 4

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

Question 5

Ions

Answer 5

When an atom loses of gains electrons meaning it is no longer neutral and will have an overall charge

Question 6

Time of Flight Mass Spectrometry

Answer 6

Records the time it takes for ions of each isotope to reach a detector. Spectra can be produced showing each isotope present

Question 7

Ionisation

Answer 7

A sample of an element is vapourised and injected into the mass spectrometer where a high voltage is passed over the chamber. This causes electrons to be removed from the atoms.

Question 8

Acceleration

Answer 8

These positively charged ions are then accelerated towards a negatively charged detection plate

Question 9

Ion Drift

Answer 9

The ions are then deflected by a magnetic field into a curved path. The radius of their path is dependent on the charge and mass of the ion

Question 10

Detection

Answer 10

When the positive ions hit the negatively charged detection plate, they gain an electron producing a flow of charge. The greater the abundance, the greater the current produced

Question 11

Analysis

Answer 11

These current values are then used in combination with the flight times to produce a spectra print-out with the relative abundance of each isotope displayed

Question 12

Spin

Answer 12

Electrons in the same orbital must have opposite spin, which is represented by arrows

Question 13

Ionisation Energy

Answer 13

The minimum energy required to remove one mole of electrons from one mole of atoms in a gaseous state

Question 14

First Ionisation Energy along a period

Answer 14

Increases due to decreasing atomic radius and greater electrostatic forces of attraction

Question 15

First Ionisation Energy down a group

Answer 15

Decreases due to an increasing atomic radius and shielding which reduces the effect of the electrostatic forces of attraction