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Periodicity key terms
Use these key terms for Periodicity in AQA Chemistry 7405. The page is built from approved learning objectives for this topic and links back to the wider unit, topic hub, and related revision assets.
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key terms
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Topic
Periodicity
Key terms
s block elements
Elements in the periodic table that have their outermost electrons in the s orbital, including groups 1 and 2.
p block elements
Elements in the periodic table that have their outermost electrons in the p orbital, including groups 13 to 18. In Classification, p block elements is used to explain classify elements as s, p, d or f block from their position in the Periodic Table with A-Level Chemistry precision.
Proton Number
The number of protons in the nucleus of an atom, which determines the element's identity and its position in the periodic table.
Periodic Table Position
The location of an element in the periodic table, which is determined by its proton number and electronic configuration.
block classification
The categorization of elements in the periodic table based on their electron configuration, specifically into s, p, d, or f blocks.
electron configuration
The distribution of electrons in an atom's orbitals, which determines its position in the periodic table and its chemical properties.
atomic radius
The distance from the nucleus of an atom to the outermost shell of electrons, which decreases across a period due to increased nuclear charge.
periodic trend
A predictable pattern observed in the properties of elements across periods in the periodic table, such as atomic radius and ionization energy.
first ionisation energy
The energy required to remove one mole of electrons from one mole of gaseous atoms to form one mole of gaseous ions.
Period 3
The third row of the periodic table, containing the elements sodium (Na), magnesium (Mg), aluminium (Al), silicon (Si), phosphorus (P), sulfur (S), chlorine (Cl), and argon (Ar).
melting point
The temperature at which a solid becomes a liquid. In Physical properties of Period 3 elements, melting point is used to explain explain melting point trends across Period 3 using structure and bonding with A-Level Chemistry precision.
bonding
The interaction that holds atoms together in a molecule or compound. In Physical properties of Period 3 elements, bonding is used to explain explain melting point trends across Period 3 using structure and bonding with A-Level Chemistry precision.
periodic data
Information derived from the periodic table that shows trends in properties such as atomic radius, ionisation energy, and melting points.
trends in properties
Patterns observed in the physical and chemical properties of elements as you move across or down the periodic table.