Modern Periodic Law and Table Structure
Properties of elements are periodic functions of their atomic numbers, which orders the elements into periods and groups by electronic configuration.
What is Modern Periodic Law and Table Structure?
Properties of elements are periodic functions of their atomic numbers, which orders the elements into periods and groups by electronic configuration.
Key formula / rule: Group number relates to the number of valence electrons.
Key points
- Identify the block, period and group of an element from its configuration.
- Explain the periodicity of properties in terms of configuration.
Common exam trap
Ordering elements by atomic mass instead of atomic number.
Definitions
- Term
Modern Periodic Law and Table Structure
- Meaning
Properties of elements are periodic functions of their atomic numbers, which orders the elements into periods and groups by electronic configuration.
- Term
Modern Periodic Law and Table Structure — explanation
- Meaning
Blocks correspond to the subshell being filled, so position on the table is a direct read-out of valence configuration. This is why chemical similarity runs down a group.
Learning objectives
Identify the block, period and group of an element from its configuration.
Explain the periodicity of properties in terms of configuration.
Formulae
- Key point
Group number relates to the number of valence electrons.
- Key point
s, p, d and f blocks correspond to the subshell being filled.
- Key point
Period number equals the principal quantum number of the valence shell.
Common mistakes
Ordering elements by atomic mass instead of atomic number.
Assigning transition metals a fixed group valency.
Keywords
Modern
Periodic
Table
Structure
Practice preview
The Modern Periodic Law states that the physical and chemical properties of elements are periodic functions of their:…
easy
How many periods are present in the long form of the Modern Periodic Table?…
easy
Elements in which block of the Modern Periodic Table have their last electron entering an s-orbital?…
easy