Chemistry AS Questions
Physical
1. Atomic Structure
Definition questions
Mass number – the sum of protons and neutrons in the nucleus
Relative atomic molecular mass – the average mass of 1 atom/ 1 twelfth of the mass of an
atom of 12C
First ionisation energy - the energy required to remove 1 mole of electrons from 1 mole of
gaseous atoms
Theory questions
Explain why the second ionisation energy of Mg is greater than the first ionisation energy of
Mg?
The electrons being removed is close to the nucleus and Mg + is more positive than Mg
State how vaporised atoms of Z are converted into Z+ ions in a mass spectrometer
Electron impact ionisation occurs so high speed electrons are fired at the gaseous sample to
knock out an electron from their outer shell to form positive ions
Explain briefly how relative abundance of an ion is measured in a mass spectrometer?
The positive ion hits the detector and gains an electron this causes a current due to the flow of
electrons. Current is proportional to the abundance of that isotope.
State why isotopes of an element have the same chemical properties
Same electron configuration/ same number of electrons
State why more than the minimum energy is not used to ionise the sample of indium
This is so no more than 1 electron is knocked out of its outer shell and further ionisation energy
cannot occur
State one reason why the first ionisation energy of Rb is lower than the first ionisation energy
of sodium
More shielding further away from the nucleus because of more shells which means it is easier to
remove the outer electron
Predict whether 88 Sr or 87 Rb has a larger radius
87 Rb has a larger radius because it has less protons but the same shielding
Explain why the value you have calculated is slightly different from the relative atomic mass
given in the periodic table?
The Ar in the periodic table takes into account other isotopes
Explain why the mass spectrum of Kr has a very small peak at a m/z value of 42?
, The 84 Kr isotope has 2 electrons knocked from the outer shell
Which one of the fundamental particles would not be deflected by an electric field?
Neutron
Write an equation for the reaction that occurs when tellurium ion hits the detector
Reverse normal equation no gaseous state needed
Predict whether 124 Te or 130 Te has a larger radius
Same atomic radius because of same number of protons and electrons
Deduce which of Na+ and Mg2+ is the smaller ion
Mg2+ - It has a stronger nuclear charge and the shielding is the same
Explain why the first ionisation energy of sulphur is different from that of Phosphorus
Sulphur has two electrons paired in a 3p orbital which causes mutual repulsion between the
electrons which makes it easier to remove the valence electron.
State which elements Mg or Al has a lower ionisation energy and explain why
Aluminium has the lower ionisation energy
Aluminium valence electron is in the 3p subshell which is a higher energy level than the 3s
subshell where the valence electron of Mg is on. The further form the nucleus the electron is
the less energy required to remove the electron.
Sate two difference between the plum pudding model and the model of atomic structure used
today
It has electron shells
Its has a nucleus that has protons and neutrons
2. Amount of Substance
Definition questions
Empirical Formula – The simplest whole number ratio of atoms of each element in the
compound
Concordant titres – titres that are within 0.1cm3 of each other
Theory questions
Suggest 1 possible danger when a metal carbonate is reacted with an acid in a seal flask
Build up of gas can lead to an explosion
Suggest 1 way a company producing pure boron could increase its profits from this reaction
Sell HCL and for any reaction sell waste products
Physical
1. Atomic Structure
Definition questions
Mass number – the sum of protons and neutrons in the nucleus
Relative atomic molecular mass – the average mass of 1 atom/ 1 twelfth of the mass of an
atom of 12C
First ionisation energy - the energy required to remove 1 mole of electrons from 1 mole of
gaseous atoms
Theory questions
Explain why the second ionisation energy of Mg is greater than the first ionisation energy of
Mg?
The electrons being removed is close to the nucleus and Mg + is more positive than Mg
State how vaporised atoms of Z are converted into Z+ ions in a mass spectrometer
Electron impact ionisation occurs so high speed electrons are fired at the gaseous sample to
knock out an electron from their outer shell to form positive ions
Explain briefly how relative abundance of an ion is measured in a mass spectrometer?
The positive ion hits the detector and gains an electron this causes a current due to the flow of
electrons. Current is proportional to the abundance of that isotope.
State why isotopes of an element have the same chemical properties
Same electron configuration/ same number of electrons
State why more than the minimum energy is not used to ionise the sample of indium
This is so no more than 1 electron is knocked out of its outer shell and further ionisation energy
cannot occur
State one reason why the first ionisation energy of Rb is lower than the first ionisation energy
of sodium
More shielding further away from the nucleus because of more shells which means it is easier to
remove the outer electron
Predict whether 88 Sr or 87 Rb has a larger radius
87 Rb has a larger radius because it has less protons but the same shielding
Explain why the value you have calculated is slightly different from the relative atomic mass
given in the periodic table?
The Ar in the periodic table takes into account other isotopes
Explain why the mass spectrum of Kr has a very small peak at a m/z value of 42?
, The 84 Kr isotope has 2 electrons knocked from the outer shell
Which one of the fundamental particles would not be deflected by an electric field?
Neutron
Write an equation for the reaction that occurs when tellurium ion hits the detector
Reverse normal equation no gaseous state needed
Predict whether 124 Te or 130 Te has a larger radius
Same atomic radius because of same number of protons and electrons
Deduce which of Na+ and Mg2+ is the smaller ion
Mg2+ - It has a stronger nuclear charge and the shielding is the same
Explain why the first ionisation energy of sulphur is different from that of Phosphorus
Sulphur has two electrons paired in a 3p orbital which causes mutual repulsion between the
electrons which makes it easier to remove the valence electron.
State which elements Mg or Al has a lower ionisation energy and explain why
Aluminium has the lower ionisation energy
Aluminium valence electron is in the 3p subshell which is a higher energy level than the 3s
subshell where the valence electron of Mg is on. The further form the nucleus the electron is
the less energy required to remove the electron.
Sate two difference between the plum pudding model and the model of atomic structure used
today
It has electron shells
Its has a nucleus that has protons and neutrons
2. Amount of Substance
Definition questions
Empirical Formula – The simplest whole number ratio of atoms of each element in the
compound
Concordant titres – titres that are within 0.1cm3 of each other
Theory questions
Suggest 1 possible danger when a metal carbonate is reacted with an acid in a seal flask
Build up of gas can lead to an explosion
Suggest 1 way a company producing pure boron could increase its profits from this reaction
Sell HCL and for any reaction sell waste products
