Atomic structure

Question 1

which types of substances is electron impact ionisation used for

Answer 1

those with a low formula mass as larger molecules can fragment

Question 2

describe electron impact ionisation

Answer 2

vapourised sample is injected at low pressure and high energy electrons are fired at it which knock an electron off

Question 3

describe electropray ionisation

Answer 3

sample dissolved in a volatile, polar solvent. Injected through a fine needle and a high voltage is applied, causing the substance to gain a proton

Question 4

describe acceleration

Answer 4

ions accelerate in an electric field to constant kinetic energy. ligheter particles go faster

Question 5

ion drift

Answer 5

ions drift through flight tube. smaller ones go faster

Question 6

detection

Answer 6

hit negative detection plate ad generate current. size of current is proportional to abundance

Question 7

how to identify the full molecule in a mass spectrum with fragments

Answer 7

the one with the highest mr (furthest right on x axis) is the full molecule

Question 8

what do orbitals represent

Answer 8

the probability that an electron will be found within a certain area around the nucleus

Question 9

what fills up first- 4s or 3d subshell

Answer 9

4s fills first, so we write them in that order

Question 10

are ions lost from 4s or 3d first

Answer 10

lost from 4s first

Question 11

what is unique about the structure of Cr and Cu

Answer 11

they have a half-filled 4s subshell

Question 12

factors that affect ionisation energies

Answer 12

atomic radius, atomic charge, shielding

Question 13

why is there a drop in first ionisation energy from P to S

Answer 13

S has two paired electrons in the orbital which repel so it makes it easier to remove them

Question 14

why is the bond angle dexreased when there are lone pairs

Answer 14

lone pairs repel more than bonding pairs
so they repel to be as far apart as possible