Atomic Structure -Physical Chemistry

Question 1

What are protons and neutrons in the nucleus sometimes referred to and why

Answer 1

Nucleons and this is because they are found in the nucleus

Question 2

How are protons and neutrons held together in the centre of an atoms

Answer 2

By strong nuclear force

Question 3

How is strong nuclear force able to overcome repulsion between protons in the nucleus

Answer 3

Because it is much stronger than electrostatic forces but can only work over short distances

Question 4

What does the letter Z represent

Answer 4

The atomic number

Question 5

What does the letter A represent

Answer 5

The mass number

Question 6

What do the number of electrons determine

Answer 6

It determines the chemical properties of an element and how it reacts

Question 7

What does the atomic number define

Answer 7

The chemical identity of the element

Question 8

What are isotopes

Answer 8

They are elements that have the same number of protons but different amount of neutrons

Question 9

How is it that different isotopes of the same element will react chemically in the same way

Answer 9

As they have the same electron configuration

Question 10

What is abundance

Answer 10

It’s how much if the element is present in the atomsphere

Question 11

How many electrons can the 3rd she’ll hold

Answer 11

Up to 18

Question 12

What is a mass spectrometer used to determine

Answer 12

The relative atomic mass of a substance

Question 13

Why is the apparatus contained in a vaccum

Answer 13

To prevent the ions that are formed Colliding with molecules in the air

Question 14

What happens in ionistation

Answer 14

The sample to be investigated is dissolved in a volitale solvent and forced through a hollow needle which is connected to the positive terminal of a high voltage supply, tiny positively charged droplets are produced as their electrons have been lost to the positive charge of supply. The solvent evaporates into the vaccum and the droplets get smaller in size till they become no more than one positively charged ion

Question 15

What happens in acceleration

Answer 15

A negatively charged plate is used to attract the positively charged ion and the ions accelerate towards the plate at high speeds the highly charged and lighter ions will move at a higher speed

Question 16

What happens in ion shift

Answer 16

The ions will pass through a negatively charged plate a beam will then form and travel along a tube known as a flight tube to the detector

Question 17

What is detection in the mass spectrometer

Answer 17

When ions with same charge arrive at the detector the lighter ones will go first due to having higher velocities the flight times will be recorded. after the positive ions will pick up an electron from the detector and this will cause current to flow

Question 18

What happens I. Data analysis

Answer 18

The signal fri. The detector is then passed to the computer and this will generate mass spectrum

Question 19

What do different atomic orbitals have

Answer 19

They have different energies

Question 20

Give the order of sub levels in the atomic orbitals

Answer 20

S P D F

Question 21

Give the order of the atomic orbitals with their main level and sub levels

Answer 21

1s 2s 2p 3s 3p 4s 3d 4p 4d

Question 22

Why is 3D after 4s

Answer 22

As it has a slightly higher enegry level

Question 23

How many electrons do the a orbitals hold

Answer 23

2

Question 24

How many orbitals do the P orbitals hold

Answer 24

6

Question 25

How many electrons do the D orbitals hold

Answer 25

10

Question 26

What property do electrons have

Answer 26

Spin

Question 27

What is first ionisation energy

Answer 27

The amount of energy needed to remove one electron from an element in a gasesous sate

Question 28

What is second ionisation enegry

Answer 28

The amount of energy needed to remove an electron from a positive Ion

Question 29

Why is more enegry needed to remove second electron

Answer 29

As it is being removed from a + 1 ion

Question 30

Why does ionisation enegry increase across a period

Answer 30

As the nuclear charge increases this due to more protons being added and so the attraction to the nucleus is stronger

Question 31

Why does helium have the highest ionistation enegry

Answer 31

As there is no shielding and it’s electrons are very close to it’s nucleus

Question 32

Why does ionistation enegry decrease down a group

Answer 32

Because the outer electrons are further away from nucleus and the attraction is less due to shielding from inner electrons

Question 33

Although across a period ionisation enegry increases why does magnesium have a higher ionisation energy than aluminium

Answer 33

As aluminium outer electron is in the 3 p orbital and is further away from the nucleus so it’s easier to remove

Question 34

What two things are measured for isotopes

Answer 34

Mass charge ratio

Abundance

Question 35

Although they are electrons in the same orbital why does phosphorus have an higher ionisation energy than slicon

Answer 35

As in slicon it has a pair of electrons in it’s outer shell and because they pair up their is a repulsion and so it’s makes it easier to remove so the ionisation energy is smaller

Question 36

Why do ionic compounds shatter easily

Answer 36

Because when they are given a sharp blow there structure dislodges and a a lattice of alternating positive and negative ions forms and the like charges come in contact and they repel

Question 37

What two things are measured for isotopes

Answer 37

Mass charge ratio

Abundance

Question 38

In the mass spec what does the last peak tell us

Answer 38

The relative molecular mass ion

Ie 86

Question 39

Describe the structure and bonding in graphite

Answer 39

Layer of carbon atoms

Macromolecules with strong covalent bonds spread out throughout the structure

Weak van der waals forces between its atoms

Layers slide over one another