1:Atomic Structure and The Periodic Table

Question 1

What is relative atomic mass?

Answer 1

It is the weighted mean mass of an atom of an element, compared to 1/12 of the mass of an atom of Carbon-12.

Question 2

What is relative isotopic mass?

Answer 2

It is the mass of an atom of an isotope compared to 1/12 of the mass of an atom of carbon-12

Question 3

How do you calculate relative atomic mass?

Answer 3

(Isotopic abundance x isotopic mass number) / total isotopic abundance

Question 4

What are the four stages of mass spectrometry?

Answer 4

1) Ionisation
2) Acceleration
3) Deflection
4) Detection

Question 5

What happens at the ionisation stage of mass spectrometry?

Answer 5

There are 2 ways ionisation can happen: Electronspray or Electron Impact

• Electronspray: proton is taken off solvent which attaches to the sample making it positively charged
• Electron Impact: sample is heated then, electrons are used to hit electrons off the sample to make it positively charged.

Question 6

What happens at the acceleration stage of mass spectrometry

Answer 6

Particles are all given the same amount of kinetic energy and then accelerated. The lighter particles travel faster

Question 7

What happens at the deflection stage of mass spectrometry

Answer 7

A magnet is used to deflect the particles towards a detection sheet

Question 8

What happens at the detection stage of mass spectrometry

Answer 8

1) The ions hit a negatively charged plate.
2) This causes a current and the size of this current gives a measure of the number of molecules hitting the plate.
3) This gives the abundance of the molecule.

Question 9

How many electrons can an orbital hold?

Answer 9

Up to 2

Question 10

How many orbitals are in the s-shell?

Answer 10

1

Question 11

How many electrons can the s-shell hold?

Answer 11

2

Question 12

How many orbitals are in the p-shell?

Answer 12

3

Question 13

How many electrons can the p-shell hold?

Answer 13

6

Question 14

How many orbitals are in the d-shell?

Answer 14

5

Question 15

How many electrons can the d-shell hold?

Answer 15

10

Question 16

How many electrons can the first quantum shell hold?

Answer 16

2

Question 17

How many electrons can the second quantum shell hold?

Answer 17

8

Question 18

How many electrons can the third quantum shell hold?

Answer 18

18

Question 19

How many electrons can the fourth quantum shell hold?

Answer 19

32

Question 20

What is spin-pairing?

Answer 20

When 2 electrons occupy 1 orbital they ‘spin’ in opposite directions

Question 21

What is the ground state?

Answer 21

The electron shell closest the the nucleus.

Question 22

What happens when an electron absorbs energy?

Answer 22

It moves up to a higher quantum shell, eventually the electron will move back down and release this energy

Question 23

How does the emission spectra provide evidence for quantum shells?

Answer 23

Radiation emitted will have a fixed frequency as the energy shells are fixed (electrons can’t exist between shells). The defined line that the spectra shows that electrons exist in shells only

Question 24

What is ionisation energy?

Answer 24

The minimum amount of energy required to to remove 1 mole of electrons from 1 mole of atoms in a gaseous state.

Question 25

When should you use the term relative formula mass?

Answer 25

When talking about a giant compound

Question 26

What is an isotope?

Answer 26

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

Question 27

What is successive ionisation energy?

Answer 27

The amount of energy needed to remove multiple electrons from an ion in successive steps

Question 28

What are the two trends in ionisation energy?

Answer 28

Across a period -> increases Down a group -> decreases

Question 29

Why does ionisation energy increase as you go across a period?

Answer 29

Number of protons increase, so there is an increased electrostatic attraction between valence electron and nucleus

Question 30

Why does ionisation energy decrease as you go down a group?

Answer 30

There is an increased atomic radius, due to more quantum shells. More shielding leads to less electrostatic attraction between valence electron.

Question 31

What is an orbital?

Answer 31

A region within an atom that can hold up to two electrons with opposite spins

Question 32

What is the shape of an s-orbital?

Answer 32

Spherical

Question 33

What is the shape of a p-orbital?

Answer 33

Dumbbell shaped

Question 34

What is a quantum shell?

Answer 34

The energy level of an electron

Question 35

What is Hund’s rule?

Answer 35

Electrons will occupy the orbitals singly before pairing takes place

Question 36

What is periodicity?

Answer 36

A regularly repeating pattern of atomic, physical and chemical properties with increasing atomic number