Topic 1: Atomic Structure

Question 1

Atomic Number

Answer 1

(Z) No. protons in an atom

Question 2

Relative Atomic Mass

Answer 2

(A) No. protons + neutrons in an atom

Question 3

Isotopes

Answer 3

Same protons, different neutrons

Question 4

Energy level (shells) vs energy

Answer 4

Higher the energy level the higher the energy the further from the nucleus they are

Question 5

Orbitals

Answer 5

Each holds 2 electrons and is a region of space around the nucleus where an electron is most likely to be found.

Question 6

Order of filling electrons

Answer 6

1s,2s,2p,3s,3p,4s,3d,4p (just draw the diagram)

Question 7

Cromium (Cr) Electron Configuration

Answer 7

(1s2 2s2 2p6 3s2 3p6) 4s1 5d5 Exception to have more stability with its half filled 3d orbital

Question 8

Copper Electron Configuration

Answer 8

(1s2 2s2 2p6 3s2 3p6) 4s1 3d10 Exception to have more stability with its full filled 3d orbital

Question 9

Ionisation Energy

Answer 9

Energy required to remove a mole of electrons from a mole of gaseous atoms to form one mole of gaseous ions.

Question 10

Ionisation Energy Trend

Answer 10

Across period - increases - increased nuclear charge, smaller atomic radii
Down group - decreases - increased shielding

Question 11

Jumps in ionisation energy in an element

Answer 11

Due to change in energy level, can determine what element it is from.

Question 12

Mass Spec Stages

Answer 12

1) Ionisation
2) Acceleration
3) Ion Drift
4) Detection
(5) Data Analysis)

Question 13

Electron Bombardment

Answer 13

Using an electron gun fire high energy electrons at the sample, this knocks an electron off the atoms creating 1+ ions.

Question 14

Acceleration

Answer 14

All have the same kinetic energy, lighter ions will travel faster because of KE= 1/mv^2.

Question 15

Ion Drift

Answer 15

Allows for separation between lighter and heavier ions.

Question 16

Detection

Answer 16

As ions hit the ion detector, a current is induced (think of it accepting the electrons which in itself is a current). The greater the current, the higher the abundance.

Question 17

m/z

Answer 17

mass/charge (if charge is 1 then this is just the mass)

Question 18

Relative Atomic Mass Calculation

Answer 18

((mass1xabundance1) + (mass2xabundance2))/total abundance

Question 19

Electrospray Ionisation

Answer 19

• Sample dissolved in volatile solvent
• Forced through fine needle connected to positive side of high voltage supply
• Produces tiny droplets which have gained a proton from the solvent
• Solvent evapourates in in vaccum so droplets get smaller
• Only single positively charged ions are left

Question 20

Kinetic Energy Equation

Answer 20

KE = 1/2 MV^2