C1 - Atomic Structure

Question 1

Are the physical properties different or the same for isotopes?

Answer 1

Physical properties are different for each isotope

Question 2

Are chemical properties different or the same for each isotope?

Answer 2

Chemical properties are the same because the electron configuration is the same

Question 3

What is the relative mass of an electron?

Answer 3

1/1840

Question 4

What is the definition of relative atomic mass (Ar)?

Answer 4

It is the average mass of an atom of an element relative to a 1/12th of the mass of carbon 12

Question 5

What does the mass spectrometer do?

Answer 5

It gives accurate information about relative isotopic masses and the relative abundance of isotopes

Question 6

What are the uses of a mass spectrometer?

Answer 6

It can be used to identify elements and determine the relative molecular mass

Question 7

What are the stages of a Time of Flight (TOF) mass spectrometer?

Answer 7

1. Electrospray ionisation/Electron impact
2. Acceleration
3. Ion drift
4. Ion detection
5. Data analysis

Question 8

What is electrospray ionisation?

Answer 8

A sample is dissolved in a solvent and then injected through a capillary tube, with a high voltage at the tip of the needle. A proton is added to the particle ionising it and giving it a charge of +1

Question 9

What is electron impact?

Answer 9

A sample is vapourised then high energy electrons are fired at it by an electron gun. This knocks off an electron forming a +1 ion.

Question 10

What is acceleration?

Answer 10

The positive ions are accelerated using an electric field so they all have a constant kinetic energy

Question 11

What is ion drift?

Answer 11

Ions travel through through a tube at varying speeds depending on the mass of the atom.

Question 12

What is detection?

Answer 12

Positive ions hit a negatively charged plate. These ions are then discharged by gaining an electron from the plate. The movement of electrons creates a current, with the size of the current measuring the number of ions

Question 13

What is data analysis?

Answer 13

Shows the mass to charge ratio (m/z) and abundance of each ion.
Need to -1 from mass on when electrospray is used, because of +1 proton.

Question 14

How many electrons can be in each sub-level?

Answer 14

s = 2
p = 6
d = 10
f = 14

Question 15

What is the order of levels and sub-levels?

Answer 15

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

Question 16

What are the 2 exceptions when filling up sub-levels?

Answer 16

Copper and Chromium
They go 4s1 then 3d rather than 4s2 3d

Question 17

How do transition metals lose electrons when forming ions?

Answer 17

The 4s electrons are removed before the 3d electrons as 4s is the outer shell

Question 18

What is the first ionisation energy of an element?

Answer 18

The energy needed to remove 1 electron from each atom of an element in 1 mole of gaseous atoms, to form 1 mole of gaseous ions with a +1 charge.

Question 19

What is the second ionisation energy?

Answer 19

The energy needed to remove 1 electron from each ion of an element in 1 mole of gaseous +1 ions to form 1 mole of gaseous ions with a +2 charge.

Question 20

How many orbits does each sub-level have?

Answer 20

s = 1
p = 3
d = 5
f = 7

Question 21

How do electrons fill up orbits?

Answer 21

Fill up all the empty orbits before they have to pair up, creating mutual repulsion. Up electron is filled before down electron

Question 22

How does the first ionisation energy change in a period?

Answer 22

Increases from s1 to s2 before decreasing for p1 as a higher energy orbit requires less energy to remove an electron. It increases from p1 to p3 before decreasing again at p4 as mutual repulsion makes it easier to remove an electron. From p4 to p6 it increases.

Question 23

Why is a sodium atom larger than a chlorine atom?

Answer 23

A chlorine atom has more protons in its nucleus than a sodium atom does. Both of these atoms have 3 electron levels. So electrons in a chlorine atom are more strongly attracted to the nucleus, meaning that it is smaller than a sodium atom despite having a larger Ar