Unit 1: Section 1 - Atomic Structure

Question 0

What are the relative masses and charges of protons, neutrons and electrons ?

Answer 0

Proton - 1, +1
Neutron - 1, 0
Electron - 1/2000, -1

Question 1

What three types of particles are atoms made up of?

Answer 1

Protons, neutrons, electrons

Question 2

What’s the difference between the mass number and the atomic number?

Answer 2

Mass number is the total number of protons and neutrons where as the atomic number is just the number of protons

Question 3

What is an ion?

Answer 3

A charged particle

Question 4

Does the mass or atomic number of an element never change?

Answer 4

Atomic number

Question 6

What is an isotope?

Answer 6

Elements that have the same number of protons but different numbers of neutrons

Question 7

What was John Dalton’s model for the atom?

Answer 7

A solid particle with no space, surrounded by an atmosphere of heat

Question 8

How did John Dalton’s model explain the states of elements?

Answer 8

Amount of heat decided the state

Question 9

What was another name for JJ Thomon’s Model?

Answer 9

There were negatively charged electrons in a sphere of positive charge

Question 10

What was Ernest Rutherford’s model for the atom?

Answer 10

There was a positively charged nucleus surrounded by orbiting electrons

Question 11

What was Niels Bohr’s model for the atom?

Answer 11

Similar to Rutherford’s but instead the electrons were in shells

Question 12

What were the four basic principles of Bohr’s earlier models?

Answer 12

1. ) electrons only exist in fixed shells and not anywhere in between
2. ) each shell has fixed energy
3. ) when an electron moves between shells electromagnetic radiation is emitted or absorbed
4. ) cause of the fixed shell energy the radiation will have a fixed frequency

Question 13

What did the Rutherford find from the gold foil experiment?

Answer 13

From the plum pudding model they expected all the alpha particles to be slightly deflected because of the positive charged sphere. However most passed straight through and only a tiny number were deflected, showing there was only a small positive nucleus and not a sphere.

Question 14

What is relative atomic mass?

Answer 14

The average mass of an atom compared to one twelfth of the mass of an atom of carbon - 12

Question 15

What is relative isotopic mass?

Answer 15

The average mass of an atom of an isotope of an element compared to one twelfth of the mass of an atom of carbon - 12

Question 16

How do you calculate the relative atomic mass from the percentages of isotopes?

Answer 16

(isotopic masse x percentages) / total percentage

Question 17

What is relative molecular mass?

Answer 17

The average mass of a molecule compared to one twelfth of the mass of an atom of carbon - 12

Question 18

What is relative formula mass similar too?

Answer 18

Relative molecular mass

Question 19

What are the names of the five steps that happen during mass spectrometry?

Answer 19

1. ) vaporisation
2. ) ionisation
3. ) acceleration
4. ) deflection
5. ) detection

Question 20

What happens during vaporisation?

Answer 20

The sample is heated and vaporised into a gas

Question 21

What happen during ionisation?

Answer 21

High energy electrons are fired out of an electron gun towards the sample, to knock of electrons and ionise them

Question 22

What happens during acceleration?

Answer 22

The positive in is accelerated by an electric field

Question 23

What happens during deflection?

Answer 23

A magnetic field is used to deflect the positive ions around the bend

Question 24

What happens during detection?

Answer 24

As ions hit the detector they cause a current to flow , the bigger the current the ore of an isotope present?

Question 25

Are ions with a larger or smaller mass/charge ratio deflected more?

Answer 25

smaller, ones with a smaller mass

Question 26

What graph is produced at the end of mass spectrometry?

Answer 26

Mass spectra

Question 27

What are the two main things a mass spectrometry can tell us?

Answer 27

Relative isotopic mass and the relative abundance of isotopes

Question 28

On a mass spectra what do the y and x axis represent?

Answer 28

X - mass/charge ratio

Y - relative abundance

Question 29

From a mass spectra of a molecular sample what do you use to find the Mr?

Answer 29

The furthest peak

Question 30

Why on a mass spectra of a molecular sample will you have clusters of different peaks?

Answer 30

During ionisation the electrons can break the molecule up into fragments, so the peaks are from different compounds within the molecular sample

Question 31

What is another name for an electron shell?

Answer 31

Energy level

Question 32

Do closer of further away shells have more energy?

Answer 32

Further, the highest energy level

Question 33

What are shells divided up into?

Answer 33

Sub levels

Question 34

What are the names of the first three orbitals?

Answer 34

S, P and D

Question 35

How many orbitals are there in the s, p and d orbitals and how many electrons do each one contain?

Answer 35

S, 1 orbital, 2 electrons
P, 3 orbitals, 6 electrons
D, 5 orbitals, 10 electrons

Question 36

What is the number of electrons and how they are arranged within an atom called?

Answer 36

Electron configuration

Question 37

How would you show the electron configuration of neon if it has 10 electrons?

Answer 37

1S2, 2P2, 2P6

Question 38

How could you show electron configuration using arrows in boxes?

Answer 38

There are boxes to represent each orbital, separated or together depending on the sub level and two arrows in each orbitals to represent the electrons, the arrows point in opposite directions

Question 39

Do you fill the 3d or 4s orbital first and why?

Answer 39

4s as it has a lower energy level than 3d

Question 40

What order to all the sub levels go into including the energy level?

Answer 40

1s, 2s, 2p, 3s, 3p, 3d

Question 41

What are the two main rules for figuring out electron configuration?

Answer 41

1. ) electrons fill the lowest energy sub shells first

2. ) electrons fill orbitals singly before they start sharing

Question 42

What is meant by shortened electron configuration?

Answer 42

When you replace some of the orbitals with the noble gas in a square bracket. The noble gas contains the orbitals you are replacing

Question 43

Which two elements don’t follow the normal electron configuration rules?

Answer 43

Copper and chromium

Question 44

Why don’t copper and chromium follow the normal electron configuration rules?

Answer 44

They donate one of their 4s electrons to the 3d sub-shell. As they are happier with either a stable full or half full d sub level

Question 45

What is the electron configuration of Chromium (it contains 24 electrons)?

Answer 45

1s2, 2s2, 2p2, 3s2, 3p6, 3d5, 4s1

Question 46

What is the electron configuration of Copper (it contains 29 electrons)?

Answer 46

1s2, 2s2, 2p2, 3s2, 3p6, 3d10, 4s1

Question 47

From left to right along the periodic table how do the sub levels go?

Answer 47

S, D then P

Question 48

What is the definition of first ionisation energy?

Answer 48

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

Question 49

How would you write the equation for the first ionisation energy of O?

Answer 49

O(g) ——> O+(g) + e-

Question 50

Can you write equations for first ionisation energy of the atoms as solids as why?

Answer 50

No they must be in the gaseous state as ionisation energies are measured for gaseous atoms

Question 51

What are the main three things that can affect ionisation energy?

Answer 51

1. ) nuclear charge
2. ) distance from nucleus
3. ) shielding

Question 52

How does nuclear charge affect ionisation energy?

Answer 52

The more protons there are in the nucleus, the more positively charged the nucleus is and the stronger the attraction for the electrons, increasing the ionisation energy

Question 53

How does distance from the nucleus affect ionisation energy?

Answer 53

Electrons further away from the nucleus won’t be as strongly and therefore have a smaller ionisation energy

Question 54

How does shielding affect ionisation energy?

Answer 54

As the number of energy levels increases so do the number of electrons between the outer electrons and the nucleus increases. This means the outer electrons feel less attraction and so the ionisation energy decreases

Question 55

What is the definition of second ionisation energy?

Answer 55

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

Question 56

Why are second ionisation energies often more than first ionisation energy?

Answer 56

The electron I going to be removed from a positive ion and will require more energy

Question 57

What is the general trend for ionisation energies across periods?

Answer 57

General increase

Question 58

Why does the first ionisation energy drop between group 2 and 3 along a period (from magnesium to aluminium)?

Answer 58

Aluminium a outer electron is in the 3p orbital on its own, so it is has a slightly higher energy level so it is further away from the nucleas, there is also increased shielding because of this. This means there is less attraction so less energy is needed to take away the electron and so reducing the first ionisation energy

Question 59

Why does the first ionisation energy drop between group 5 and 6 along a period (from phosphorus to sulfur)?

Answer 59

In phosphorus the electron is being removed from a singly occupied orbital , in sulphur the electron is being removed from an orbital containing two electrons. There is repulsion between these two electrons so it is easier to removed reducing the first ionisation energy.