Atomic Strucutre

Question 1

Name the Fundamental Particles.

Answer 1

Electron, Neutron and Proton

Question 2

What is the Mass/Kg, Charge, Relative Charge and Relative Mass of a Proton?

Answer 2

The Mass/Kg is 1.673x10-27​​, the Charge is 1.602x10-19​, the Relative Charge is +1 and the Relative Mass is 1.

Question 3

What is the Mass/Kg, Charge, Relative Charge and Relative Mass of a Neutron?

Answer 3

The Mass/Kg is 1.675x10-27​, the Charge is 0​, the Relative Charge is 0 and the Relative Mass is 1.

Question 4

What is the Mass/Kg, Charge, Relative Charge and Relative Mass of a Electron?

Answer 4

The Mass/Kg is 9.109x10-31​, the Charge is 1.602x10-19​, the Relative Charge is -1 and the Relative Mass is 5.45x10^-4.

Question 5

What is the order of Electron Configurartion?

Answer 5

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

Question 6

How many charges can each letter of the Electron Configuration hold?

Answer 6

S can hold up to 2, P can hold up to 6, D can hold up to 10 and F can hold up to 14.

Question 7

Electrons fill energy levels (Shells) from orbitals closest to the Nucleus and then move outwards. How many Electrons does each orbital hold?

Answer 7

1st: 2 electrons, 2nd: 8 electrons, 3rd: 18 electrons and 4th: 32 electrons.

Question 8

What is the definition of an Ion?

Answer 8

An Ion is a particle which has either lost or gained an electron.

Question 9

What is the Mass Number (The larger number) in the periodic table?

Answer 9

It is the amount of p+ (Protons) + n (Neutrons) in an atom.

Question 10

What is the Atomic Number (The smaller number) in the periodic table?

Answer 10

The Number of p+ (Protons) in the nucleus of the atom, the atomic number defines the chemical identity of the element but also represents the number of e- (Electrons) in the atom.

Question 11

What are Isotopes?

Answer 11

Isotopes are atoms with the same number of p+ (Protons) but different numbers of n (Neutrons), hence with different mass numbers.

Question 12

Provide a feature of isotopes.

Answer 12

Different isotopes of the same element react chemically in the same way as they have the same number of e-.​

or

Different isotopes of the same element have different physical properties, eg. diffusion rate and nuclear properties eg. radioactivity.​

or

Isotopes that are non-radioactive are called stable isotopes eg. Cl-35 and Cl-37​

Question 13

How do you work our Relative Atomic Mass (Ar) using Average Mass of an Atom of an Element?

Answer 13

Ar = Average Mass of an Atom of an Element / 1/12th mass of one atom of C-12

Question 14

How do you work our Relative Atomic Mass (Ar) using Isotopic Masses and Percentage Abundance?

Answer 14

Ar = (Sum of Isotopic Masses) x Percentage Abundance​ / Total Percentage

Question 15

How do you work our Molecular Mass (Mr) using Average Mass of one Molecule?

Answer 15

Mr = Average Mass of one Molecule / 1/12th mass of one atom of C-12.

Question 16

What are the 6 steps for TOF Mass Spectrometer?

Answer 16

1. Vaporisation
2. Ionisation
3. Electric Field
4. Ion Drift
5. Detector
6. Mass Spectrum

Question 17

What happens in the Vaporisation (1st) step of Mass Spectrometer?

Answer 17

Samples of unknown substances (elements or compounds) are injected into a vacuum.

Question 18

What happens in the Ionisation (2nd) step of Mass Spectrometer?

Answer 18

The substances injected into the vacuum are then ionised into positive ions by firing electrons at them (knocking off electrons from the outer energy level). This is called Electron Impact Ionisation.

Question 19

What happens in the Electric Field or Acceleration (3rd) step of Mass Spectrometer?

Answer 19

The beam of ions leave the field with constant speed and constant kinetic energy. The beam of particles moves into the flight tube where there is no electrical field and are allowed to drift.​
Ions with lower m/z ratios drift faster than those with larger m/z ratios.​

Question 20

What happens in the Ion Drift (4th) step of Mass Spectrometer?

Answer 20

The beam of ions leave the field with constant speed and constant kinetic energy. The beam of particles moves into the flight tube where there is no electrical field and are allowed to drift.​
Ions with lower m/z ratios drift faster than those with larger m/z ratios.​

Question 21

What happens in the Detector (5th) step of Mass Spectrometer?

Answer 21

The detector detects the current generated as the positively charged particles hit the plate and records how long it took to drift through the chamber. This is then used to generate the m/z values needed to produce the mass spectrum.​
Particles with lower m/z ratios reach the detector first as they drift faster.​
The position of each peak on the spectrum is related to the m/z charge of the ions. Since most ions have a +1 charge this is the same as the mass of the ion. The size of each peak is proportional to the abundance of the ion in the sample.

Question 22

What happens in the Mass Spectrum (6th) step of Mass Spectrometer?

Answer 22

The results then will make a graph in which it states not only the elements or compounds in the Mass Spectrometer but also their relative abundance %.

Question 23

What happens in Soft Ionisation?

Answer 23

The sample is dissolved in a volatile solvent.​

Tiny positive droplets are produced by injecting the solution through a needle to the positive terminal of a high voltage supply. Particles lose electrons.​

The solvent evaporates leaving single positively charged ions​

Note: Mr increases by 1​

Question 24

Using Mass Spectrum I see that 89% of my material has a Relative Atomic Mass of 88, 10% has a Relative Atomic Mass of 87 and 1% has a Relative Atomic Mass of 86. What is the element?

Answer 24

First you turn the percentages into decimals, and then you multiply the percentage by the Relative Atomic Mass of that piece. So 0.89 x 88 = 78.32, 0.1 x 87 = 8.7 and 0.01 x 86 = 0.86. If you add all of those up you get 87.88 as the Relative Atomic Mass is 87.88 the only element close is 38 Strontium which has a Relative Atomic mass of 87.62.

Question 25

What is Avogadro’s Constant?

Answer 25

6.022 x 10^23 mol^-1