1.1 atomic structure

Question 1

Relative atomic mass

Answer 1

Average mass of an atom of an element / 1/12 mass of 1 atom of C12

Question 2

First ionisation energy + equation

Answer 2

Energy need to remove 1 mole of electron from each atom in 1 mole gaseous atom to from 1 mole of gaseous 1+ ion

X (g) -> X+ (g) + e-

Question 3

electrospray ionisation + give equation

Answer 3

• dissolve in solvent
• needle at high voltage
• gain proton (H+)

X(g) + H+ -> XH+(g)

Question 4

why need ionised

Answer 4

• accelerate by electric field
• create current when hit detector

Question 5

electron impact ionisation
?***

Answer 5

• bombarded at high energy electron
• lose electron

Question 6

alpha particle scattering experiment

Answer 6

• pass straight through = empty space
• deflected = +ve concentrated central nucleus

Question 7

plum pudding vs nuclear

Answer 7

• solid +ve sphere; mostly empty space except nucleus
• +ve spread evenly throughout sphere; +ve central nucleus
• mass spread evenly throughout sphere; concentrated in nucleus
• electron embedded evenly; orbit around central nucleus

~~~

Question 8

1st ionisation energy general trend across ->

Answer 8

• increase
• more proton
• same shell + shielding (smaller atomic radius)
• stronger attraction for outer electron

Question 9

why 1st ionisation energy decrease 2->3

Answer 9

• higher energy level + shielding (p orbital)
• higher in energy/ further away from nucleus/ weaker attraction between nucleus + electron

Question 10

time of flight calculation

Answer 10

1. find mass of 1 ion in kg
   (m/ Mr x n)
2. KE = 0.5mv^2
3. s=d/t

Question 11

relative abundance calculation

Answer 11

∑ (isotopic mass x relative abundance) / total relative abundance

Question 12

% abundance calculation

Answer 12

∑ (isotopic mass x % abundance) / 100

Question 13

why 1st ionisation energy decrease 5->6

Answer 13

• electron pair up in p orbital
• repel