A-Level Chemistry Edexcel 9CH0

know the structure of an atom in terms of electrons, protons and neutrons

understand how mass spectrometry can be used to determine the relative molecular mass of a molecule

Limited to the m/z value for the molecular ion, M⁺, giving the relative molecular mass of the molecule.

be able to define the terms ‘first ionisation energy’ and ‘successive ionisation energies’

understand how ionisation energies are influenced by the number of protons, the electron shielding and the electron sub-shell from which the electron is removed

understand reasons for the general increase in first ionisation energy across a period

understand reasons for the decrease in first ionisation energy down a group

understand how ideas about electronic configuration developed from:

i) the fact that atomic emission spectra provide evidence for the existence of quantum shells ii) the fact that successive ionisation energies provide evidence for the existenceof quantum shells and the group to which the element belongs iii) the fact that the first ionisation energy of successive elements providesevidence for electron sub-shells

know the number of electrons that can fill the first four quantum shells

know that an orbital is a region within an atom that can hold up to two electrons with opposite spins

know the shape of an s-orbital and a p-orbital

know the number of electrons that occupy s, p and d-subshells

know the relative mass and relative charge of protons, neutrons and electrons

know that electrons fill subshells singly, before pairing up, and that two electrons in the same orbital must have opposite spins

be able to predict the electronic configurations, using 1s notation and electrons-in-boxes notation, of:

i) atoms, given the atomic number, Z, up to Z = 36 ii) ions, given the atomic number, Z, and the ionic charge, for s and p block ions only, up to Z = 36

know that elements can be classified as s, p and d-block elements

understand that electronic configuration determines the chemical properties of an element

understand periodicity in terms of a repeating pattern across different periods

understand reasons for the trends in the following properties of the elements from periods 2 and 3 of the Periodic Table:

i) the melting and boiling temperatures of the elements, based on given data, in terms of structure and bonding ii) ionisation energy based on given data or recall of the plots of ionisation energy versus atomic number

be able to illustrate periodicity using data, including electronic configurations, atomic radii, melting and boiling temperatures and first ionisation energies

know what is meant by the terms ‘atomic (proton) number’ and ‘mass number’

be able to determine the number of each type of sub-atomic particle in an atom, molecule or ion from the atomic (proton) number and mass number

understand the term ‘isotopes’

be able to define the terms ‘relative isotopic mass’ and ‘relative atomic mass’, based on the ¹²C scale

understand the terms ‘relative molecular mass’ and ‘relative formula mass’, including calculating these values from relative atomic masses

*Definitions of these terms will not be expected. The term ‘relative formula mass’ should be used for compounds with giant structures. *

be able to analyse and interpret data from mass spectrometry to calculate relative atomic mass from relative abundance of isotopes and vice versa

be able to predict the mass spectra, including relative peak heights, for diatomic molecules, including chlorine