Physical Chapter 1: Atomic Structure

Question 1

What subatomic particles make up atoms?

Answer 1

Protons, Electrons, and Neutrons

Question 2

Where is most of the mass of an atom?

Answer 2

In the nucleus

Question 3

What part of the atom makes up most of the volume?

Answer 3

Orbitals

Question 4

What is the relative charge of an electron?

Answer 4

-1

Question 5

What is the relative charge of a proton?

Answer 5

+1

Question 6

What letter represents the mass number?

Answer 6

A

Question 7

What letter represents proton number?

Answer 7

Z

Question 8

What does the mass number represent?

Answer 8

Protons + Neutrons

Question 9

What does Atomic number represent?

Answer 9

Number of protons

Question 10

What is the relative mass of an electron?

Answer 10

1/2000
(negligible)

Question 11

How are positive ions formed?

Answer 11

Atoms lose electrons

Question 12

How are negative ions formed?

Answer 12

Atoms gain electrons

Question 13

What is the relative mass of protons & neutrons?

Answer 13

1

Question 14

What is an isotope?

Answer 14

Atoms with the same number of protons & electrons but different numbers of neutrons

Question 15

Why do isotopes have the same chemical properties?

Answer 15

They have the same electron configuration

Question 16

Why do isotopes have slightly different physical properties?

Answer 16

Physical properties tend to depend on the mass of an atom - isotopes have diferent mass

Question 17

What was the order of atomic models?

Answer 17

Dalton Model - solid spheres
Plum Pudding Model
Rutherford model
Bohr Model
Refined Bohr model

Question 18

What was the ‘solid sphere’ model?

Answer 18

All atoms are solid spheres, and different spheres make up different elements.

Question 19

What was the ‘Plum Pudding’ model?

Answer 19

Electrons stuck in a large positively charged ball of ‘pudding’

Question 20

What was the Rutherford Model?

Answer 20

Most of the atom is empty space, positively charged nucleus is surrounded by a ‘cloud’ of electrons.
Discovered by the alpha particle experiment

Question 21

What was the Bohr Model?

Answer 21

Electrons exist in shells or orbitals of fixed energy.
Discovered via experimental observations of radiation emitted.

Question 22

What was the refinement made to the Bohr model?

Answer 22

Electrons exist in sub-shells, not just shells.
Discovered due to electrons in the same shell not having the same energy.

Question 23

What is the definition of relative mass?

Answer 23

The mass of one mole of an atom comapred to 1/12 Carbon-12.
(can be used as Relative molecular & relative isotopic mass as well)

Question 24

How do you measure relative mass?

Answer 24

Mass spectrometry

Question 25

What are the 4 stages of mass spectrometry?

Answer 25

Ionisation Acceleration Ion Drift Detection

Question 26

How does Ionisation work in TOF Mass spectrometry?

Answer 26

There are two methods: Electrospray Ionisation - A sample is dissolved & pushed through a small nozzle at high pressure. A high voltage is applied to it, adding an H+ ion to each sample, forming a gas of positive ions. Electron impact ionisation: The sample is vaporised & an electron gun fires electrons at it, knocking electrons off of it & forming +1 ions.

Question 27

How does acceleration work in TOF Mass spectrometry?

Answer 27

The positievly charged ions are accelerated by an electric field so that they all have the same kinetic energy. This means the lighter ions will move faster.

Question 28

How does Ion Drift work in TOF Mass spectrometry?

Answer 28

The ions enter a region with no electric field, so they just drift through it. Lighter ions will drift through faster than heavier ions.

Question 29

How does Detection work in TOF Mass spectrometry?

Answer 29

Lighter ions travel at higher speeds, so they're detected first. The Detector detects charged particles first, and a mass spectrum is produced.

Question 30

What is the difference between mass spectra of electron impact ionisation & electrospray ionisation?

Answer 30

Electrospray ionisation mass spectra will have peaks that are one unit greater than the relative mass of each isotope. Electron impact ionisation mass spectra have peaks that are equal to the relative mass of each isotope.

Question 31

What is TOF Mass Spectrometry?

Answer 31

Time of Flight Mass Spectrometry

Question 32

How do you find Relative atomic mass from a mass spectrum?

Answer 32

Multiply every relative isotopic mass by its percentage abundance & add them together, then divide by 100

Question 33

What is the order in which sub-shells fill?

Answer 33

Question 34

How are orbitals filled?

Answer 34

Electrons fill orbitals singly before they fill up doubly.

Question 35

What are the two exceptions to the rule regarding transition metal electron structures?

Answer 35

Chromium & Copper donate 4s electrons to the 3d sub-shell, as it's more stable. When they become ions, they lose the 4s electrons before their 3d electrons.

Question 36

What determined chemical properties?

Answer 36

Electron Structure

Question 37

What is ionisation energy?

Answer 37

The energy needed to remove an electron from each atom in 1 mole of gaseous atoms to form 1 mole of gaseous ions

Question 38

What are the 3 factors affecting ionisation energy?

Answer 38

Nuclear Charge - Greater nuclear charge means greater Ionisation energy Atomic Radius - Greater atomic radius means lower ionisation energy Shielding - greater shielding means lower ionisation energy

Question 39

What is the definition of second ionisation energy?

Answer 39

The energy needed to remove one electron from each ion in 1 mole of gaseous 1+ ions to form 1 mole of gaseous 2+ ions

Question 40

What is the trend of successive ionisation energies within each shell?

Answer 40

They increase

Question 41

What causes a large increase in ionisation energy?

Answer 41

Change in shell

Question 42

What is the trend in ionisation energy down a group? What causes this?

Answer 42

Decreases Greater shielding as you go down the group, as well as greater atomic radius

Question 43

What is the trend in ionisation energy across a period? What causes this?

Answer 43

Increases There is stronger nuclear attraction, whereas atomic radius & shileding barely change

Question 44

WHy is there a drop in ionisation energy across a period between groups 2 & 3?

Answer 44

It shows sub-shell structure: the p orbital has a slightly higher energy, so is further away from the nucleus, as well as experiencing slightly higher shielding from the s electrons.

Question 45

Why is there a drop in ionisation energy between groups 5 & 6?

Answer 45

Electron repulsion - Shileding is identical, but the electron is removed froma paired orbital, meaning it's easier to remove due to electron repulsion.