S3.1 Periodic Table Flashcards
how atomic radii in noble gases was measured
freezing = close as possible = measure
periodicity
repeating pattern of a property
periodicity trends
- ionisation energy
- electron affinity
- electronegativity
- atomic size/radii
- reactivity
Metal properties
- malleable
- lustrous
- high m.p
- high thermal & electrical conductivity
- tendency to losse e-
Non metal properties
- brittle
- dull
- low melting points
- low conductivity
- tendency to gain electrons
Metalloid properties
- both metal & non metal
- high m.p
- intermediate conductivity
- lustrous
- brittle
Atomic size trend
measured as covalent radius in half the distance between nuclei
* size decreases going across period
* size increases going down group
Atomic size trend - Period
- decreases
- nuclear charge increases
- larger attractive force between shell and nucleus
- pulls electrons closer => smaller size
Ionisation trend - Group
- decreases
- shielding effect = hinders attraction between nucleus & shell
- easier to lose e-
Atomic size trend - Group
- increases
- shells increase
- less attraction
- shielding effect
Ionisation trend - Period
- increases
- charge increases = larger attraction
- more difficult to lose e-
Ionic Radius
based on nuclear charge to outer electron ratio
When answering periodicity questions
SANDI
shielding
attraction
nuclear charge
distance
ionisation
Electron affinity
the energy change when 1 mole of electrons is added to 1 mole of gaseous atoms to form 1 mole of gaseous ions
Electronegativity Trend - Period
- increases
- nuclear charge increases = greater attractive force
