An atom of an element with the same number of protons, but different number of neutrons.

An average value that takes account of the abundance of the isotopes of the element.

The sum of the atomic masses of all the atoms in a molecule.

The ion produced when the molecule is ionised by loss of an electron from the molecule.

An apparatus used for recording and measuring spectra, especially as a method of analysis.

Mass spectrometry

Chemistry

Instrumental analysis and flame tests: red for lithium

Chemical tests: aqueous ions (including zinc)

Identifying unknown substances (including zinc)

Ionic equations: aqueous ion tests

In the Groups of the Periodic Table unit, pupils learned about the properties and reactivity of elements in the same group.

This unit covers tests to identify aqueous cations and anions, including flame tests for metal ions like lithium, sodium, and copper. It explains the benefits of instrumental analysis, such as sensitivity and accuracy, and focuses on interpreting results from charts, tables, and spectroscopy data.

Chemical analysis

What does the M⁺ peak represent in a mass spectrum?

What does fragmentation in mass spectrometry help identify?

(mass of isotope 1 × abundance) + (mass of isotope 2 × abundance)/100

How is the relative atomic mass calculated using mass spectrometry data?

A molecule with an unequal number of protons and neutrons.

A molecule that has formed a covalent bond.

An ion produced when the molecule is ionised by loss of an electron.

Calculate the relative atomic mass of bromine, given isotopes Br-79 (50.7%) and Br-81 (49.3%). Give your answer to one decimal place. 

Calculate the relative atomic mass of neon, given isotopes Ne-20 (90.48%), Ne-21 (0.27%), Ne-22 (9.25%). Give your answer to two decimal places. 

What do isotopes of an element have in common?

Atoms form {{}} when they gain or lose electrons.

How do you calculate the number of neutrons in an atom?

Which subatomic particle determines the identity of an element?

The total mass of an element's isotopes combined.

An average value that takes account of the abundance of the isotopes.

The mass of the most abundant isotope of an element.

The mass of one mole of the element in grams.

What does the relative atomic mass of an element represent?

What is the relative atomic mass of chlorine, given isotopes Cl-35 (75%) and Cl-37 (25%)?

Mass spectrometry

Lesson outcome