An atom of nitrogen can form a nitride ion with an electronic configuration of 1s²2s²2p⁶.

State the formula of the nitride ion.

An element forms an ion, W, with a single negative charge that has the same electron configuration as the nitride ion.

State the formula of W.

An element forms an ion, R, with a single positive charge that has a full 3p sub-shell as its highest energy level.

State the formula of R.

Define the term isotope.

Define the term relative atomic mass.

Calculate the relative atomic mass of silicon using information in the table below.

Give your answer to two decimal places.

In the late 1800s physist JJ Thomson discovered the electron. He proposed the 'plum pudding' model of the atom whereby negatively-charged electrons were distributed evenly throughout a sphere of positive charge.

The figure below shows an atom of element Q using the ‘plum pudding’ model.

An atom of Q contains eight electrons.

State two differences between the ‘plum pudding’ model and the model of atomic structure used today.

Deduce the full electron configuration of an atom of element Q.

Complete the missing values in the table to show the numbers of sub-atomic particles in an atom and an ion of magnesium.

Explain why different isotopes of magnesium have similar chemical properties.

This question is about the isotopes of krypton.

A sample of krypton containing the isotopes ⁸²Kr, ⁸³Kr, ⁸⁴Kr and ⁸⁶Kr has a relative atomic mass of 83.8.

The sample contains 11.6% each of the ⁸²Kr and ⁸³Kr isotopes.

Calculate the percentage abundance of each of the other two isotopes.

Give your answers to one decimal place.

A sample of krypton is analysed in a time of flight (TOF) mass spectrometer.

Give two reasons why the isotopes of krypton must be ionised before they can be analysed in a TOF mass spectrometer.

A ⁸⁴Kr⁺ ion travels along a flight tube of length 1.50 m

The ion has a constant kinetic energy (E_k) of 2.052 × 10^–13 J

m = mass of the ion (kg)

v = speed of ion (ms^–1)

Calculate the time, in s, for the ⁸⁴Kr⁺ ion to travel down the flight tube to reach the detector.

Assume the mass of the ⁸⁴Kr⁺ ion is the same as the mass of an ⁸⁴Kr atom.

Give your answer in standard form to two significant figures.

The Avogadro constant, L = 6.022 × 10²³ mol^–1

Give the full electronic configuration of an atom of sulfur.

Give the full electronic configuration of a copper(II) ion.

Time of flight mass spectrometry is used to analyse a sample of tin.

The sample is ionised by electron impact to form 1+ ions.

The mass spectrum of this sample of tin has four peaks.

Data from the spectrum is shown in the table below.

Give the symbol, including mass number, of the ion that reaches the detector first.

Calculate the relative atomic mass of tin in this sample.

Give your answer to one decimal place.

This question is about atomic structure.

Define the mass number of an atom.

The table below gives some isotopic information about an atom and an ion of nickel. 

Identify the missing values A-D.

A sample of nickel contains three isotopes, ⁵⁸Ni, ⁶⁰Ni and ⁶²Ni.

This sample has a relative atomic mass of 58.7

In this sample the ratio of abundance of isotopes ⁶⁰Ni and ⁶²Ni is 7:1

Calculate the percentage abundance of ⁵⁸Ni in this sample.

Give your answer to one decimal place.

The figure below is a model proposed by Rutherford to show the structure of an atom.

State two features of the current model that are not shown in the Rutherford model.

State the number of electrons that can fill the first 4 energy levels.

First energy level = electrons

Second energy level = electrons

Third energy level = electrons

Fourth energy level = electrons

Time of flight mass spectrometry can be used to analyse biological molecules such as the amino acid, tryptophan (Trp). Trp is ionised by electrospray ionisation and its mass spectrum is shown below.

Describe the process of electrospray ionisation.

Write an expression to represent the ionisation of Trp in this process.

What is the relative molecular mass of Trp?

A molecule P is ionised by electron impact in a TOF mass spectrometer.

The P⁺ ion has a kinetic energy of 1.85 x 10^–15 J

This ion takes 1.62 x 10^–5 s to reach the detector.

The length of the flight tube is 1.80 m.

Calculate the relative molecular mass of P.

This question is about time of flight (TOF) mass spectrometry.

In a TOF mass spectrometer, explain how:

i) ions are accelerated;

ii) ions are detected, and

iii) the abudance of ions is determined.

Calculate the mass, in kg, of a single ⁵²Cr⁺ ion.

Assume that the mass of a ⁵²Cr⁺ ion is the same as that of a ⁵²Cr atom. 

The Avogadro constant, L, = 6.022 x 10²³ mol^‒1

Give your answer to 2 significant figures.

In a TOF mass spectrometer the kinetic energy (E_k) of a ⁵²Cr⁺ ion was 6.482 x 10⁻¹⁴ J

Calculate the velocity of the ion using the equation:

m = mass (kg)

v = velocity (ms^-1)

Give your answer in standard form to two significant figures.

Bromine has two isotopes, ⁷⁹Br and ⁸¹Br, in approximately equal abundance. In a TOF mass spectrometer bromine forms ions with formula [Br₂]⁺

Sketch the pattern of peaks you would expect to see in the mass spectrum of a sample of bromine.

A sample of iron, which consists of three isotopes, has a relative atomic mass of 55.909. The isotopic information for two of the isotopes is shown in the table below. The data for one of the isotopes, ^mFe, is missing.

Use this data to calculate m, the mass number of ^mFe.

This question is about time-of-flight mass spectrometry.

The acceleration of positive ions is a fundamental process in a time-of-flight mass spectrometer. 

Explain how this process allows the instrument to separate ions of different masses.

The mass spectrum of a sample of selenium is shown below.

Use this spectrum to calculate the relative atomic mass of this sample of selenium.

Give your answer to one decimal place.

Explain why the A_r value of selenium you have calculated differs slightly from the relative atomic mass given in the Periodic Table.

This question is about isotopes.

Most elements contain atoms of different isotopes.

State one similarity and one difference between the atomic structures of isotopes of the same element.

Mass spectrometry can be used to identify the isotopes of chlorine.

Part of the mass spectrum of chlorine is shown below.

Calculate the relative atomic mass of chlorine.

Give your answer to two decimal places.

Three molecular ion peaks, M⁺, are found in the mass spectrum of chlorine, Cl₂.

The three M⁺ peaks have m/z values of 70, 72 and 74 respectively.

Suggest why each M⁺ peak is observed. 

Elements are arranged into blocks in the Periodic Table based on their electron configuration.

We now know that electrons are in shells; shells have sub-shells and sub-shells have orbitals.

Define the term orbital.

State the maximum number of electrons which can fill each region of an atom:

The 2s orbital: electrons

The 2p orbital:  electrons

The 3d sub-shell: electrons

The third energy level: electrons

Write the full electronic configuration of an atom of copper. 

An atom has 2 more protons and 5 more neutrons than an atom of ⁶⁵Zn.

Write the symbol, including the mass number, for this atom:

Draw the shape of an s orbital and the shape of a p orbital.